I think this calls for a complete change of tack...
The whole exercise should be about gettting the best vehicle for the trip back...one which will have the greatest 'offending potential' along your chosen route...
Afterall everyone near Dc will be offended to some degree...(after living there for 5 years I found myself offensive let alone others
)...
So head south in a besloganed foreign car... head north in a massive gas guzzler spewing fumes.. either way you need to focus on offending the maximm number of people in the minimum time....what a great challenge..
Just as an example when I lived in the US I drove.. with a good buddy of mine a little Hyundai sedan (red on red on red) from Red Bluff in Ca all the way to Vermont via SF/LA to Corpus Christi in TX... Mobile, New Orleans...the Outer Banks in NC to DC and then up to NYC and north..
I leave to your vivid imaginations the different reactions we received in the various parts of the country....
I guess that leaves the original purpose of the thread a bit redundant..