Originally Posted by Elux
Bumping my list.
International Police Wagon
Cadillac Series 61 Touring Sedan
Hudson Super Six
The International Police Wagon can be found at the crime scene for "The Driver's Seat." It's the van they put the arrested suspects in.
The Hudson Super Six I found at the intersection of 4th and Los Angeles St. You can find it parked at the garage there called Scott's Garage (Or something similar) or its driving around in the area.