Flim Demon in Jar/ Cars

Good evening, I been trying to search for this movie for about a decade. It was somethingrecorded on to a VHS; the tape no longer exists (prob pre 2002). The film starts with a struggling, but talented mechanic who is discovered by a fancy-pants man who invites him to a party. At the party the mechanic sees his car collection, and finds a demon/alien baby in a jar with curtains in the room shrouding the jar credenza. Mechanic makes a deal to be famous. Later in the movie there is a scene where they found a rare car where a limited amount were made; they used another years make to sell for lots of money. The mechanic uses magnesium or something to change the VIN. Any help is appreciated. Thank you for reading!

the darkling