1990 BTCC
Vauxhall started the season with a single entry for John Cleland in the #50 car. A second car for Chris Hodgetts, running as #70, would appear at Oulton Park, initially in rear-wheel drive format but converted to FWD by the following meeting. The second car continued for the remainder of the season with Hodgetts, David Coulthard, Bob Berridge and Markus Oestreich all taking turns behind the wheel. There were a number of differences in the roll-cage design which help distinguish between the two cars.
From the head-on view you can see that the cross-over point in the diagonal roll-cage braces is higher on the #50 car. Although fairly clear when viewed side-by-side that difference is less obvious when viewed in isolation as it can be easily masked by the camera angle. The difference is more pronounced from the side view. On the #50 car the rear section of the roll cage visible through the side window is at a much shallower angle and extends the full width of the window, whereas on the #70 car the brace disappears below the bottom of the window much further forwards.

We know that the #70 car was chassis number 011, and is generally considered to be the first car to be built. It would be reasonable therefore to assume that Cleland's #50 car could that be chassis number 012.
Vauxhall Cavalier / Opel Vectra A
Vauxhall Cavalier / Opel Vectra A
Built : 1990
Chassis : 011
1991 BTCC
The team started the year with two newly built cars - John Cleland in the #5 car and Jeff Allam in the #6 entry. The'91-spec cars can be identified by changes to roll cage design from the previous year.
From the head-on view you can see an extra diagonal brace from the middle of the car to the top of the passenger side B-piller. Seen from the side view, the team had reverted to the shallower angle 'full-length' diagonal rear brace.

The two 91-spec car were used until the second race of the Donington Park double-header. Nick Whale's BMW was stranded in the gravel trap having blown it's engine and spun off on it's own oil. As the leading group of cars approached several drivers hit the oil and spun off, include both Vauxhalls. Allam's car made heavy contact with Whale's stricken BMW, which left both Vauxhall and BMW writen-off. The #5 car was lucky to avoid major damage as the impact with Allam had pushed Whale's car out of Cleland's path.
For the remainder of the year Allam continued in a 91-spec car whilst Cleland was now driving an earlier 90-spec car. It's assumed that Allam had taken over Cleland's car with Cleland now using chassis 011.

At the final two meetings of the year the team ran a third car for Bob Berridge, running as #56. By comparing the three cars we can see that Berridge was in a 91-spec car, the team having built a third car to to replace the one destroyed at Donington.
We know that the third car was chassis 016, so we can assume that the original two must have been chassis 014 and 015, although this leaves a gap in sequence from the previous year.
Vauxhall Cavalier / Opel Vectra A
Vauxhall Cavalier / Opel Vectra A
Built : 1991
Chassis : 016
1992 BTCC
Vauxhall again stated the year with two newly built cars - this time John Cleland was in the #2 car and Jeff Allam in the #6 entry
The cross-over point of the roll-cage braces sits much lower so that the visible portion forms more of a V-shape, whilst the extra diagonal brace introduced in 1991 is now gone. From the side, the rear diagonal brace has gone back steeper angled design. One distinctive feature can be seen at the edges of the windscreen - the roll-cage and A-piller are joined by a small plate with 3 circular holes.

The chassis number of the 1992 cars are not known, although 017 and 018 might be reasonable assumption. There are suggestions that chassis 011 again served as the team's spare car but no evidence that it was needed for a race.

The two surviving 1991 cars were sold to Ecurie Ecosse and run by Ray Mallock Ltd (RML). David Leslie drove the #79 entry, with Bobby Vernon-Roe and Alex Portman sharing the #78 car, although it is not known who drove which chassis.
1993 BTCC
For 1993, DCRS again ran a pair of newly built cars for John Cleland and Jeff Allam, this time in the #3 and #4 entries respectively. There are no obvious external differences between the 1992 and 1993 cars.

Ecurie Ecosse were now running RML-built cars, although there were still two more DCRS-built cars on the grid. Ian Ashley was in running as #16 in chassis 011, and Ian Khan in chassis 016 as #17.

One of the 1993 cars is known to be chassis 020
Vauxhall Cavalier / Opel Vectra A
Vauxhall Cavalier / Opel Vectra A
Built : 1993
Chassis : 020-93
1994 and beyond
At the end of 1993 RML took over the running of the works Vauxhall team, meaning there were no more new DCRS-build Cavaliers, although the older cars did continue in the hands of privateers for a few more years. Ian Khan made a number of appearances in 1994 in chassis 016. Chassis 020 would be raced by Chris Goodwin in 1994 and briefly by Robb Gravett in 1995.
The distinctive 3-hole A-piller can be seen on the factory Opel Vectras run in France in 1993/94 and Spain in 1994, indicating that these are almost certainly 1992 or 1993 DCRS-built cars. It's not known if they are ex-BTCC cars or additional builds, although could account for the missing chassis numbers.