Vents? Where precisely were the vents?
No Hammers came equipped with any sort of vent, near as I can tell and based on the 2 period Hammer sedan articles I have in my library. They had a ducktail spoiler on the trunklid (sometimes molded-on, as a Coupe I've an article on), side sill extensions, and the classic AMG front air dam. And they were quite low. As to wheels, most seem to have come with Aero I style, but with body-colored centers (centres for you blokes out there); the '90 Coupe Hammer I have a review on had chromies, though.
Please elaborate on the vents, as perhaps it was some sort of add-on done since Aufrecht, Melcher and the boys had their hands on it.
If he turns out to be just a poser, run him off the road the next time you see him