i just want to make one where the top is just a few inches thick of aluminum or something like that, then when you mess it up you can just grind it down.
I bought some shelving which could also be built as a workbench and used some offcuts of kitchen worktop screwed/glued to these units to form a decent workspace.
And my little car fits perfectly and I still have plenty of workspace inside the garage both in front of and around the car
Overall I'm happy with this - it was cheap (£30 for shelving units, worktop was spare plus a few screws etc)