ORIGINAL: rctom
Actually I had the cow idea a long time ago, but with regular irregular spots, not bunnies. It's cute!
Some years ago there was a drag racing nitro funny car sponsored by the California Milk advisory board. As you might guess it was all painted up like a cow.
For fun one day they mounted an extra parachute bag on the back and filled it with cow manure.
As they approached the starting line, engines blasting and everyone's attention focused on the two cars, the driver pulled the chute release causing it to appear that the cow car took a dump.
NHRA did not see the humor, I laughed my ass off.
TF
Well, in the case of the Yak, just use brown smoke.