Very true, but you're a decade or two late for that. IIRC Cash4Clunkers put like a $3k floor on used car value (~$5-7k in today's dollars) meaning you'd never sell your old car for $2k to an individual when you could sell it to the government for $3k.

Per google it was started in 2009, which means any car worth less than $5k around 17 years ago isn't materially impacting new or used car prices today.