I had same general issue with my Toyota 4runner. All I have to offer is general common sense (my version of it) which worked for me:
A) There wasn’t that much choice/variance in where I could position my vehicle (I suspect this is true for you as well)…a few inches of play front to back, and a little less left-to-right, so that sort of removed these variables from the equation for me. I assumed L-t-R symmetry with regard to frame, and that motor at front makes it heavier there, so that led me to center it as closely as I could L-t-R, and a bit off center with regard to F-t-B such that front end had more support.
- Raising lift slowly, I kept checking underneath to make sure contact would be made somewhere along frame, front and back, for both sides. I needed to take care to make sure “soft” areas (e.g. muffler, gas tank, other weak-support surfaces) would not make first contact by using appropriately positioned rubber lift pads and 6" lengths of 2x4s.
iii) Once those were in what I thought were correct positions, I raised the lift until my car just barely moved, then rechecked all 4 touch points and re-positioned as needed.
IV) All this checking and positioning and re-checking and re-positioning at all four lift points can take a long time and goes much faster if you have a friend. I don’t so it took me about 15-20 mins 1st time to get to a point where I felt I could lift vehicle safely and that I wasn’t going to damage it.
&) Once you get it right, raise the car to eye level, take some pics so you don’t have to go through this horrible procedure next time, and save your 2x4s if you had to use them.