[Graham]

As far as I remember, I used the same guide for both cars, and trimmed them down.
I obviously trimmed one a little better than the other (or set the front wheels bump stop a little lower on the Porsche) !
Fingers crossed the M1 will fare better at Shed End.

From my measurements the BMW M1 was 6.4mm depth and the Porsche 914/6 was 6mm depth