The first E class 220 a mg coupe I bought 6months old developed a gearbox problem after two weeks, took I back to my local MB dealer, not the one I bought it from, they could find no problem. Told them I would be driving to Croatia and on through Italy, France to Southern Spain, they said not a problem, they were wrong. In Spain I took it to a local MB dealer he had it for four days, said it was the g/box software and reset everything , it was fine for three weeks, until I was on the motorway coming home.
Back home took it back to Tonbridge where I bought it, they kept it a week, drove it every day and serviced it, could find nothing wrong. Had it home for a week, and the problem returned.
By now I'm really peed off,. Back to Tonbridge, told him I wanted to exchange the car, he said but its now 3 months old and you've put 6500 miles on it, after a lot of argument I stuck it out, got back what I'd paid, and bought from them a newer 220 E amg coupe with 19 inch wheels and a pan am roof, it was £2000 more than my original, so I paid them that, and they gave me back the £260 I'd just paid for its first service, I've since traded that and bought an E 350 9g coupe, and am at the moment back in Spain with it.
Sorry to make it such a long tale, but the moral is don't take no for an answer you told them of problems right from the start, and the car has not been right since you bought it, have a note of the dates and times they've had it back and don't be, fobbed off with petty excuses, be polite but firm in what you want, and good luck
