I am glad I don't get any of those problems, I take all my own and my mates cars to an mot testing station that only does mots, tyres, exhausts and batteries, they don't fail it to get the work then.
There is a scrap yard just down the road so if I get a fail on something small they pass it and let me fix it on their ramp, I'm lucky really, I had a car mot'd with them and they missed 3 failures, I pointed them out and they said if I'd kept my mouth shut it would have passed, I just said I'd rather know it has a proper mot, since then if I fail on anything small it gets fixed on the spot, anything big they pass it and just say get it done knowing i will and if my emissions are out the probe goes up another car.
It helps that i send a lot of people there for mot's and tyres and have always looked after them if they put a car on the ramp for me to have a look under it, most people just take it for granted, so when I give them £20 for putting it in the air they appreciate it, funny thing is the bloke that owns it and does my tests used to work at central tyre, I hated them and got armed police sent out to me after threatening the staff with a chainsaw, get on well with him now.