Dan
You are right considering the hassle of DOT and EPA. This also adds approx $10K to the price. Also factor in new cats at $1400each to be able to pass a cold start emissions test. + 6months of waiting in some cases....
Here are the differences
US cars are missing
-AHK - Active Rear Suspension. Greatly improves handiling, but a potential nightmare to fix...
-Headlight washers
-Blacked out front turn signals ( can easily be added)
-Rear foglights (ditto)
-Sport seats (Optional in Europe)
-Rear sunshade (Optional in Europe)
-Floating rotors
-Engine oil cooler
-Rear diff oil cooler
-Full leather (Optional in Europe)
That is more or less it. There are approx 220 US spec CSi, and hence they hold their price very well in comparision to their Euro siblings. I'm sure the gasoline and insurance prices in Europe might be to blame as well.
The only thing that the NA spec one has that the Euro doesn't is Motorsport embossed doorhandles that are very pretty IMHO.
If you have any questions at all, post them and we'll try our best to anwser.
Carl
M5 - E31 moderator team