A couple of weeks ago I asked for advice on how to permanently (or even for extended periods) attach a bike rack to a car without damaging the paint. The best functional solution suggested was to get a hitch mount rack but there is about a $400-$500 price tag attached to that by the time I get a hitch installed. Someone else suggested that I try "helicopter tape", a 8 mil, transparent and VERY tough film on the car at the contact points. Since I found that the tape wouldn't damage the paint finish and that I could try it cheaply ($10), seems logical to give it a try. Found that one of the main uses for "helicopter tape" these days is in applying essentially invisible car bras to protect paint on high end vehicles. I've got a few million miles of experience in driving around construction and gravel truck infested Atlanta and have collected many hundreds of rock chips. I can see the need for a product like this.
Just installed the tape and the rack over it yesterday. Pictures below. You have to get up close and look hard to even see that there is a tape applied to the car so I can conclude that the tape works from a visual point. There are also pieces below the two contact points below the vertical supports. I'll give it several weeks and pull the rack to examine the tape for any sign of abrasion damage or tape release or whatever.
One unintended result of the Saris bike rack always being on the car is that it gives me immunity from the red light cameras proliferating locally over the past few years. The bottom shot is a very close approximation of the angle from which the revenue generators shoot. Ain't that a heartbreaker?