If the list is based on the average repair cost as you suggest, why do the repair cost fluctuate up and down on the list?
If that was the case shouldn't Suzuki be ranked the best and Porsche the worst?
Going by my own experience as a mechanic for the past 16 odd years I would say I deal with a hell of a lot more BMW's, mercs, Audi's, VW's etc than I do any other manufacturers hence the reason I do not own one.
I've just done a deal on a Honda Civic so should be getting that in the next couple of weeks to replace my focus purely because I can't remember the last time I had to recover one for a mechanical failure so IMO Honda are one of the most reliable manufacturers out there.
It made me laugh he other day when chatting to customer whilst recovering his VW Golf to his garage, he asked me what I drove, to which I said a Focus and he just said 'I'd have thought you'd have something decent!' to which I replied 'well mine hasn't been on the back of one of these since I've had it so that's decent enough for me!' Lol! He saw funny side and said I had a point!