Dude is buying my car for $18k but he says he'll go higher if I fill-out the title transfer as a $1,000 sale price to save him money on sales tax. The $1,000 figure was way too low and I think would raise red flags at the Franchise Tax Board, but $10-12k could be reasonable and save him almost $700 in taxes. Obviously illegal, but to what degree? "Hit-and-run with tons of witnesses" or "rolling a stop sign with no one around"? Who would know?