They shouldn't fail the MOT.

Had my vectra MOT'd with mine in and nothing was said.

I think the only issues that could arrise are A) They should be fitted to lights with a non-diffused glass.

B) They should have washer jets fitted.

C) The car should have auto level adjusters for when there is a load in the back of the car.

However, MOT stations aren't normally that picky.
