We would also like to locate such a tent OR awning.  I recently got a 
catalog from CAMPMOR.  My son has a great nylon tent from them that fits 
over the bed of his Nissan p/u and allows for a dry sleeping area but 
also gives you about a 10 X 14 tent w/floor, windows & fly.  He said they 
make different models for different types of cars, trucks & vans but I 
haven't had the time to look into it yet.  The brand of tent is the 
EUREKA! The web address for Campmor is WWW.campmpr.com
They will give you an 800 number & a lot of good sale stuff.