A small four-cylinder vehicle (i.e. Honda Civic) usually painted yellow, pink, or purple and driven by a 5'5" jackass. The wagon usually has a large wing on the back, white rims, and an annoying loud muffler.
Chuck felt like he was like Fast and The Furious as he rolled through Philly in his douche wagon.
Very similar to a butt wagon, though a bit more oriented toward people who deserve a heavier term than butt wagon. A douche wagon can also safely be called a buttsnoipe, an asshaberdasher, a bunghole, etc.
{Seen on a drone flight video posted on YouTube:
While I was flying the drone, I "heard" a jingle for Bob's Discount Furniture but with altered lyrics.
To wit:
♪ Bob's Bob-O-Pedics ♪
♪ From your bµñg#Ø£€ to your ṕ€n¡s ♪
♪ Some douche wagon neutralised my socks!!! ♪
{~850ms delay}
♪ Bob's Bob-O-Pedics! ♪