Originally Posted by ilikebmxbikes
You can't go wrong with either really.
True that. If you want something a little more tuner friendly then get the N54. If you want something to modify lighter with a warranty get an N55.
I choose the N54 instead of ordering a bran new 135i and I'm really glad I did. Just rolled over 45K miles and the car has no issues at all. You can also make it unreasonably fast for public roads with way less money than you put into you VW.