How much weight can I put on a car rotisserie?

I made my Rotisserie from 75 x 75 x 5 RHS, that slips inside 89 x 89 x 5.
It is height adjustable, and balance adjustable. The hard part is making it balance, so it is easy to rotate the car.
I used 2 x 3,000 kg long ram jacks to raise and lower the body to a desired height.
I have a small gearbox to turn the body around.
It sure makes doing things easy, like welding, sanding, buffing, cleaning, etc.
Well worth it....you can see better what you are doing.