I do have a question for you though... surely it cannot be legal to perform an MOT on your own car... You could pass anything.
Did wonder about this myself, cannot see that it is right or legal to mot your own car. 
Well you both FAIL - nothing in the rules at all.

Companies can make it policy that you cannot MOT your own car ( or families ), ours does, but VOSA dont.
No different than a Sales garage MOTing their own cars really.

as stated - all down to the risk of losing not only your own job, but others at the garage and the licence to MOT again as the tester but also the MOT manager and the garage.
can you tell i am studying to become a MOT Admin
