If you measure at the sides of the lip where it's lower than the middle, my car is 3.5-4" from the ground. That's juuuuust enough to be able to make it up most driveways and entrances with some requiring mad JDM angles lol. I can tell you that the entire bottom of the lip has absolutely no paint left of it but you can't see it at all so it doesn't matter. You can use that as a guide for when you mount yours. I would say that if you're at 3" and below, expect to be looking for alternate routes to certain entrances and exits.
Oh and I did forget to mention speed bumps. I've been able to get over any speed bump I've needed to but the bigger ones I literally crawl over. There's been plenty times where the car won't even have enough momentum to make it up the speed bump and I have to give it a bit of gas. if i go any faster though, I both scrape the lip and the undercarriage.