[brian_]

My questions are will the Tesla unit fit within the stock fenders and where will the subframe mounting pads fall relative to the stock frame rails? I am not concerned about interference with the inner fender panels, gas tank, spare tire well (both to be removed) or trunk floor. I have not been able to find the dimensions that I need before committing to the project. I am looking for 1) the outside width of the stock Tesla tires, 2) the center-to-center dimensions of the four subframe mounting points relative to the rear axel centerline, 3) the height of each mounting pad above the ground, 4) the overall diameter of the stock Tesla wheel and tire combination. Also, are the mounting pads symmetrical with the centerline of the vehicle?

If you still want to use the Tesla Model 3 rear drive unit and subframe with suspension, you can check the dimensions with a CAD model. If you haven't used CAD or 3D modeling, now might be the time to start.

Depending on your interests and sense of humour, you may find SuperfastMatt's Model 3 into Jaguar project in YouTube informative and/or amusing. He shared his 3D model of the Model 3 unit (complete drive unit in subframe with suspension) in GrabCAD.

My guess would be that subframe to vehicle structure mounting points are symmetric (because there's no reason for them not to be), but that should be confirmed.

Tire dimensions for various vehicles are easiest to find from an online tire dealer, which lets you look up the make, model, and variant, then links you to tire specs. I usually use TireRack.