Alas I don't know. I reckon it'd be pretty awesome if you could convert the area above the emporium/ops office into a useable space, and have a ramp up there by the old upgrade booth, but I fear we'd be talking mega bucks to do that. Probably somewhere off the Superman plaza, so either in the heilix, or between Superman and studio admin might work though. I'm really not picturing anything to massive here, just a small building where people can wander around and have a look at real movie memorabilia, and small set mock ups. Anyone who has done the WB studio tour in LA might be able to picture what I'm seeing, as they have a museum as part of the tour.
Oh, and I don't care if I'm a monster. Such a low capacity, low grade piece of crap attraction like speedy's doesn't deserve to exsist at a shopping center never mind a proper theme park. If kids want to drive, Taz's Hollywood cars still exsist. Honestly, I'd rather see Speedy's be turned into a shady expanse of benches, and see a new ride go into Rocket Ride's old location.