I don't know, just my humble opinion, I don't really like what some are saying about the SUV idea for Soundwave.
Soundwave is a senior ranking member among the Decepticons.
A pimped out SUV alt mode would have looked too fancy. He needs something that looks "grand" rather than "fancy."
We won't know what and how cool Soundwave will be until the movie comes out. But until then, here is an alt mode I've always liked for Soundwave.
Pimped out Chrysler 300 complete with sound systems. Now this is Grandeur.
with black rims