UPDATE on Fresh Cherries as slot car bodies...
Okay, I finally had a few free minutes, so I grabbed all the Fresh Cherries cars I had and a handful of slot car chassis and started comparing. Here's what I found:
ALL the Fresh Cherries cars, even the Chevette, are too long for standard Aurora Tjet chassis. The JL and Auto World Tjets, however, have a slightly longer wheelbase than the Auroras, and the Chevette lines up just about perfectly with the JL/AW chassis in long wheelbase position. The Pinto and Mustang II will also work with this chassis, but they are slightly longer and the wheelwells might need to be modified a little.
I looked at common Tyco chassis, and I think this is probably what people are using if they are converting FC diecasts... The short wheelbase position of Tyco chassis is exactly the same as the long wheelbase of the JL/AW Tjets. The Chevette, Pinto, and Mustang II will work with Tyco short wheelbase, and the Hornet, Maverick, '71 Mustang, and Pacer will work with Tyco long wheelbase. The Hornet is a little bit TOO long, and the Pacer a little too short, but they can both be made to work. The Maverick and '71 Mustang are dead-on. The chassis that use these wheelbases are the Magnum 440 and 440X2, the HP7, and the HP2. I think these would be a blast on HP2 or HP7 chassis, as they are not quite as fast as the 440s and slide around more...
Upon actually unscrewing the diecast bases and fitting them over the slot car chassis, I made another discovery: the bodies are too narrow, meaning they'd have to be "spread" to fit over the slot car chassis mounting tabs...
--rick