Quote:
Originally Posted by
nicad2000 
OP, based on personal experience I wouldn't put a great deal of stock in the belief of substandard reliability in Infiniti products. Through undergrad I owned an Infiniti J30 up until right at the 200k mile mark - had very few issues with the car. In six years of ownership I think I only had to replace the power steering pump and the alternator, you would have a hard time matching that sort of reliability with any German competitor.
My experience with that car was so good that I now own an M45. A bit bigger, a hell of a lot faster, and still a great deal of fun. I have high hopes for such outstanding reliability in this vehicle as well.
In particular, I wouldn't worry about engine problems in the G35's or any other Nissan with the 3.5 or 3.7. That motor in one form or another has been in production for at least 15 years, has won numerous awards, and has generally had the kinks worked out over time it seems.
As far as my advice for your selection, please test drive all of your options! You'll probably find that the BMW's have more finesse than the G35, but you may fall in love with the more brutish nature of the Infiniti. I believe the BMW's, certainly the 1 series, have the edge in handling. Pick the car that you feel will make you happy on a daily basis - there's nothing like leaving after a hard day at work and sinking into a machine that you truely enjoy spending time driving.
+1. As I stated earlier, my Infiniti is the most reliable vehicle of the 3 I have. Although I much prefer the handling and features of my German built vehicles, the Infiniti gets regular fluid changes, tires, and that's it. The running costs of the others are significantly higher, and it's not due to mpg.