[denisond3]

To get the car high enough to be able to slither under it, I use those 'car ramps' I got from an auto parts store. If you live where there are curbs and are able to do it - having the car straddling the curb and driving it into the ramps will give you a very decent clearance. I keep old pieces of large cardboard boxes to put on the ground. That way its easy to slide under, even on gravel.
I also have a floor jack and bottle jacks, but they are only to raise the car - not to support it. I use 2 foot long pieces of 6 by 6 and 4 by 4 lumber laid in pyramids for supporting the car before I crawl under it. I cant safely use jackstands because my driveway is gravel, not masonry. Even so I block the rear wheels -thoroughly- before getting under it.