Car electronic boards have a lot of tanti capactors. They look like a little drop of paint on two wire legs.
They also have different markings on them from normal capactors.
There may be other sorts of tanti capactors too.

The other thing I notice is they sometimes have RAM chips with the little window in the top of them.
The windows normally covered with a sticker. They also normally are plugged into a socket.
Other chips are normally soldered in.

Do a seach here for info about the tanti capactors. Lots good info & pics



There's other electronics in cars that are valuable, I'm just not sure about it. Like I have heard that the resistance wire in the fuel tank is platinium... and similar with the tiny wire that goes thru the intake housing, as a temp probe.
I have found gold wires in the pressure sensor in the intake manafold. But, what its worth ? Dunno. Where to sell it, dunno too.