Micra - advice needed! - Gilbert'sGirl
I drive an L Reg Nissan Micra - unsurprisingly, it's my first car, and whilst it isn't remotely stylish, it's got low mileage and has been utterly reliable since I bought it.

However, I had it serviced in July at a Nissan dealership and they seem to have caused more harm than good. They swapped one tyre for the spare - fair enough, but I've taken it back to be re-aligned twice and the car still vibrates at over 60mph. This hasn't happened before. They tried to charge me for multiple unnecessary jobs - including £4 for air freshener.

I'd had the car looked at briefly beforehand by an off-duty RAC bloke, and he noticed that the cover of the catalytic converter was worn. He told me to get Nissan to remove it, but not to replace it as the car would function perfectly well without one.
Anyway, I asked them to, they charged me for the job, and I didn't think any more of it. Until yesterday, when a metal plate dropped off the bottom of my car on the M6 and scraped along the tarmac.

I managed to make it to the next junction with the plate hanging by one corner. Now it's dropped off entirely and it's about the size of an A4 piece of paper, but curved and with horizontal slits that make it look like a vent cover.

Is this the cover of my cat? Can the car cope without it? And what should I tell Nissan when I write a letter of complaint?

All advice welcome - I'm living many miles away from the person that I'd usually consult, and so I hope someone on the board might be able to assist. Thank you!
Micra - advice needed! - Aprilia
Well, it sounds as if some sort of exhaust heat shield has fallen off. It is very likely to be the cat heat shield (or part of it) - but you really need someone to check underneath to be absolutely certain.

I would think that the car is perfectly safe to drive until you can get someone to look at it (a fast-fit centre will probably check for free - but be careful, they will most likely try to sell you something).

Your vibration at 60mph is likely to be a problem with wheel balance or a distorted tyre/wheel - again not urgent, but maybe get it looked at when your exhaust is checked. Ideally you should go back to the dealer and ask them to do it properly.
Micra - advice needed! - Gilbert'sGirl
Aprilia - thank you so much for the advice.

I think that, rather than returning to Nissan, I might take the car to a local, independent mechanic, and then send them the invoice, accompanied by a stroppy letter. I can do that bit (I've got a legal background and so the complaint isn't what fazes me) but I don't know/understand the mechanics of the problems sufficiently well to make an informed complaint at the moment.

I'm really grateful - thanks again!
Micra - advice needed! - Aprilia
By modern standards your Micra is a simple car and a good independent would be a much better place to have it serviced than the Nissan dealer.

Incidentally, I don't know how much they charged you to remove the loose catalyst heat shield, but it shouldn't have been much at all (its only a few minutes work).

Value my car