I have dreamt of something really similar to this for a while. Mainly a sleeper cab with a box big enough for 2 cars end to end and maybe space for 3 or 4 if you stack'em, with a lift gate to load them. Only in my dream, the lift gate has removable center panels and maybe air jacks, to facilitate servicing the racecar at the track. Storage Boxes below with plenty of room for spares and tools.
I actually saw someone who had something kind of similar at Roebling a couple of yrs ago. Only that one didn't have a liftgate, it had tall, sketchy ramps and then more ramps inside the box, so the car sat at about a 20 or 30 degree angle when loaded.
To be clear, I don't need anything like this, can't afford the buy in or running costs, and have nowhere to keep it, but this is something my post lotto winning self would try to make happen. So cool.
https://bringatrailer.com/listing/1994-international-9600-car-hauler/