Bitchin' goes all the way back to the early 50's at least.
A very common word when I was a kid and "Bitchin' Flames" was "in".
When I was about 13 or so I "borrowed" my older brother's '40 Ford with "bitchin' flames". Wouldn't be here today if he ever found out.
Congrats on the car Steve, getting groceries is one of the advantages of a car.
Magic