LMR
Three cars (79971-3) were delivered to the LMR at Bedford MPD (79971/2 arrived in July '58) for use on the lines to Northampton and Hitchin. The depot sent two drivers and two fitters to the region's Diesel Training School at Derby and the works of Park Royal Vehicles Ltd. These men then taught the other Bedford staff, although all staff who would drive or maintain them were expected to eventually attend courses at Derby. Operations began on Monday the 11th August '58 to existing steam timings. To mark the occasion one vehicle conveyed the Mayor of Bedford, Alderman A. A. Jones, and R. L. E. Lawrence, Divisional Traffic Manager, London Area LMR on a demonstration run between Bedford and Shefford. Other civic dignitaries, local industrialists and traders, and other railway officials were also carried.

At the introduction of the winter timetable the following month (September 15th) the services were increased and accelerated. Eight new services were introduced between Bedford and Northampton, bringing the daily total up to 18, 9 in each direction. Improved timings cut the overall journey time by 2-9 mins. On the Bedford - Hitchin branch services were increased from 4 to 7 each way, with timings saving 4-12 mins. The service re-organisation also affected the 'Saturday leave train' from Henlow, which had to run empty to Shefford and wait for the railbus to pass before proceeding back to Henlow, which now only had one platform with track in situ. In October '58 7,000 passengers were carried on these services, more than twice the amount carried in Oct. '58.

Park Royal Railbus at Shefford on a demonstration run in August 58 before the introduction of services in the Bedford area.

Despite a great increase in traffic, especially on Saturdays (a Jan. '59 trip saw the 13:20 from Hitchen full from Southhill and with standing passengers from Cardington, and on Saturdays the 12:40 from Bedford was so well patronised that it reverted to regular seam haulage), their introduction was far from trouble free, and mechanical failures dogged the vehicles. They were also prone to slipping on frosty rails and in January '59 snow fall saw a complete reversion to steam.

They were replaced for long periods by steam push-and-pull trains (with a notable period in Nov. '58). On 28/4/59 two pairs of 101s arrived at Bedford, nominally to act as standby sets for the Northampton & Hitchin branches, but they saw steady use, although one disappeared about a month later. The railbuses were out of service in early July '59, with steam push and pull again in use, and in early Nov. '59 the 'buses departed to Wolverton. The local services to Hitchin and Northampton were then worked by new 108s as well as the steam push-pull. Possibly two of them returned temporarily from Wolverton, but wherever possible the diesel twins or steam was used.

Although they had gone from the Bedford - Northampton line, proposals in mid-'60 to withdraw the diesel service from the line, there was feelings that there was a lot of pontetial traffic lost due the teething troubles of the Park Royal Railbuses on the line.

From Wolverton they were sent to the ScR where they seemed to be more successful. Two of these (79972-3) returned to the LMR in Dec. 65 where they started on the Buxton to Millers Dale branch on the 3rd Jan. '66. Once again numerous difficulties were encountered and they spent much time out of use. They were replaced by German railbuses 79961/4.

ScR
The two ScR cars (79970/4) went to the Ayr area. 79970 had been noted at Southall on the 3rd December 1958.

79974 was introduced on the Ayr - Dalmellington branch on the 6th April 1959. The services consisted of four railbus trips from Dalmellington and five return on Mondays to Fridays instead of the previous two, and on Saturdays seven from Dalmellington to Ayr, including two steam, and eight return, including three steam. Certain trips were also done to Kilmarnock. It was interesting to note that in at least the 1960 timetable the Dalmellington services did not carry the second class only symbol.

On 1/8/59 the scheduled railbus turn on the Dalmellington branch at 12:40 from Ayr and 15:00 return was undertaken by a steam loco with four coaches.

In Autumn '60, the Dalmellington 'bus, still 79974, was apparently being considered for transfer to the Peterhead branch.

79970 replaced BCV 79959 on the Speyside route between Elgin, Granton-on-Spey and Aviemore in early April '59. On June 15th 1959 four new halts opened: Imperial Cottages; Gilbey's Cottages (between Carron and Knockando); Dalry Farm (between Advie and Cromdale), and Ballifurth Farm (between Gonspey East and Nethybridge), and drivers were warned of their approach by white boards stating 'Request Stop 100 Yards Ahead'. The frequency of services was also further improved and overall journey times reduced by up to 15 mins.

By August 3rd '59 79970 was out of use with a fractured frame, the services were being operated by 40648 with one LMS saloon. Wickham 79966 was soon sent north to take over. After working well from Aviemore for over a year, 79966 also succumbed to a fracture frame (was it something to do with the condition of the track?), and 79972 was sent as a replacement. But trouble was experienced with this vehicle, and by the end of Sep. '60 79970 was back on the line. It was still there in May '61.

Despite the timetable improvements and the fact that a fine view of the beautiful scenery was to had, patronage did not greatly increase. Passenger traffic was particularly sparse between the tourist centres of Granton-on-Spey and Aviemore, but receipts from the whole service was poor (it was withdrawn from October 18th 1965).

Another line which the type worked was the shuttle between Craigendoran and Arrochar on the West Highland Line. The vehicle which had started these services was Wickham 79969, but this was out of use by March '60 when 79970 was noted on trial on the line. The service was at the time in the hands of steam, and Rhu had just re-opened as Rhu Halt, which was between Helensburgh Upper and Shandon. 79971 was noted working the line on the 11/6/60. On summer Saturdays steam was diagrammed to take over, however on this date the loco, J37 64580, had failed.

79971 was noted working still on these services on the 28/1/61, but had moved to Beith by 15/3/61. It was thought the regular Beith vehicle was still in works. During the Easter '61 weekend the Craigendoran - Arrochar service was steam hauled.

The Beith regular was AC Cars 79979, which went into works at the start of 1961, and the line was first covered by 79974 from Ayr , until 79971 replaced it, from the WHL.

The Craigendoran - Arrochar shuttle was also over time worked by 2-car sets,and the service was withdrawn form the 15th June 1964.

By mid-'60 Hamilton shed had four roads given to DMU maintenance and stabling. It's railbus allocation at the time was BCVs 79958/9 and Park Royal 79972.

Ayr had the greatest concentration of railbuses in Scotland, and their use gradually increased. From February 5th 1962 further reorganisation brought about the use of railbuses on most trains on the Kilmarnock - Ardrossan - Ayr services, as well as certain workings over the Darvel branch. Services over the Dalmellington and Darvel branches as well as the Kilmarnock - Ardrossan services were withdrawn from the 6th April 1964, but they continued to be used on the Kilmarnock trains, despite an ever-growing number out of use.

Frame trouble experienced by the Wickham vehicles saw Park Royal cars replace them on the Devon Valley line. The service ran through places such as Dollar, Rumbling Bridge, Crook of Devon and Balado, and had one through journey in each direction between Perth and Stirling, enabling the vehicles to be stabled overnight at these points. Services were poorly patronised and withdrawn from the 15th June 1964.

By November '66 a mere handful remained in service and the Ayr - Kilmarnock services were covered by two of the Park Royal vehicles (79970/1), most of the other railbuses being out of use.

Not long after four AC Cars came north from the WR, two of which went to operate the Larbert - Alloa and Falkirk - Grangemouth branches, but the other two had to go to the Ayr area where there was only now one Park Royal in active use. This vehicle also made an appearance on the Alloa - Larbert service in due course.