Elliot Rodger...

[Mister Obvious]

The odd thing was that there was body fluids or brain matter under his "body" after they moved it, but nothing visible in the car.

It makes absolutely no sense whatsoever.

But my question was is there any way to ask the salvagebid.com about the final destination of it?

The longer somebody waits to call (or email) them and ask about it, the more unlikely it is to receive any answers.