As they are generally based on a Nitro buggy design which uses a driveshaft, you need an “Off-Road” starter box (with wheel mounted transversely) for 1:8 GT cars, or at the very least, a universal one as noted above.

I’ve managed to ask a few more people, and although they are the most expensive, two out of three still insist that the Hudy is the best one out there ATM. It’s just a shame that they couldn’t design theirs to be universal.