Until the car scraps the ground. That is how low they will go. As to is the work right I could not tell you. Being too low in a daily driver can be costly here in Texas. Even at stock height some speed bumb can be murder.

You can get a 1-1/2 finger gap without any issue. The one thing you need to consider if what your wheel off set is. Being that low with the wrong offset, you will rub.

 

I didn't mean they weren't suitable for track use, but they wouldn't be my first choice for it since the spring rates are so soft. Sure, you can find stiffer ones, but by the time you add that cost in there are even more good options to choose from. My $.02, YMMV...