Didn't you have any of these 'quirks' with your old forfour? No excuse for not knowing...
my old one had none of the quirks this new one has... it only ever crunched in reverse but it went in to gear every time smoothly.
raising the pedal and then trying again doesn't always work.
in regards to the other problems.
problem 2 - seams to have improved since i put a new tyre on the LR, the RR was at 6mm and the old one was between 4.5-3mm, although once i get my expense money back ill be buying a pair of new tyres for the front and then off to get it 4 wheel aligned.
problem 3 - i slackened the drive belt off and went for a run and its still squealing/gurgling, its ok until it gets above 3,500 RPM on hard acceleration, figured the coolant level may have been low just enough for it to suck air through the pipe work, so i topped it up and over filled it a little. next plan is to remove the drive belt and give it a quick run just to eliminate the pulley side of the engine.... but there is however the question of the K&N panel air filter which is fitted, would it squeal/gurgle on hard acceleration in gear but not in neutral with the clutch pedal up
problem 5 - iv managed to find a high horn but need to get hold of a low horn so i can replace wheezy for a nice Jaguar duel tone horn
problem 6 - im going to get one of the parts lad to phone a Mercedes dealer in group and get a price.
problem 7 - i think i might leave the rear wiper as it is.
i have also hit a sticky wicket as well, i know HID conversions are a gray area in regards to the MOT and i did ask Merc of Leeds if they would fail, and they said it would, but that was on my old car without headlamp power wash, but my new one has headlamp power wash...