I'm not sure how much the testers enjoy the thick rustproofing waxes on the underside of ours, they do say the cars will last for donkeys years though.

The theory of clean proves well in lorry servicing and 6 weekly inspections (they get professionally steam cleaned for annual test anyway), whenever possible i wash the vehicle and steam clean the chassis paying particular attention to under the fifth wheel trailer connection where grease accumulates heavily, far as i'm concerned its normal courtesy to present the vehicle clean for a mechanic to work on, this has paid me back a hundred fold over the years, am treated well at the dealer and all the little jobs on mine get seen to without ever having to ask.

The standard of MOT test is very inconsistent. Before the electronic system was in use that is today I had my car fail its MOT on a long list of issues and simply driven it a few streets away to another testing station where it passed with no advisory.

No two people judge wear and tear exactly the same. I have found that a garage that is more used to testing classic cars will be significantly more lenient with wear and tear items. Whilst a main dealer will often consider wear and tear items an issue if a part is not in nearly new condition.