I have seen posts from many folks thinking of doing this. The most often asked questions are about a lift system. If you have one that raises evenly and holds securely, I’m sure many folks would like to hear how you designed it.
Was she strong enough? Or did you give up on it because she wasn’t?
My own take is that I would prefer to have four lifting cables where legs would be under an L girder platform (1/5 in from edges and ends) and counterweights (one per cable) to balance the load. By using buckets for counterweights you can add weight selectively as construction proceeds, and eliminate the need for a winch.
Then, when lowered, the cables should be unloaded and the platform standing on legs. One hip-bump of a suspended platform equals 8.8 on the Richter scale!
I came up with an easier solution. The vehicles were exiled to the driveway in front of the garage door.
As to the suggestion of leaving the car on the driveway - you obviously don’t have problems with cars being vandalized (we left our other car out once and the lock got pushed in with a screwdriver[:(!]) or with really hot summers[sigh] (scorching hot car in the middle of summer, no thanks)! If these things weren’t an issue I would think about doing it that way.
I am still building my “high flying” layout, and the pulley system is working great for me still. So I shall continue along this path till I have a new place where a permament layout will be able to live BUT that is along way off.