http://www.autoblog.com/photos/top-s...rands/#image-1
If only by the slimmest of margins, Mercedes is 2nd and is about a few 100 units behind, with Lexus being 3rd and is about 1,300 units behind:
http://www.autoblog.com/photos/top-s...rands/#image-1
For those who don't wanna click through the slideshow, full rankings:
8. Lincoln (21,478 units in Q1)
7. Infiniti (33,872 units)
6. Cadillac (37,175 units)
5. Acura (39,644 units)
4. Audi (40,098 units)
3. Lexus (77,180 units)
2. Mercedes Benz (78,156 units)
1. BMW (78,492 units)
BMW's highest selling model is the 3 Series with a 47% increase in sales year over year.