So many trunk racks on the market from various prices, etc. Can anyone recommend a particular one from experience that does not scratch or damage the car and keeps the bike steady on highway or city?

I've had my Bones 2 for a couple of years. Works great, easy to install, secure, and no scratches on my Acura. Scratches would be a BIG no-no.
https://www.saris.com/index.php?page=...hk=1&Itemid=57

We've got a Bones 3 bike and have had good experiences with it. The important thing is to wipe off the feet before installing it onto the car. Otherwise, there could be grit that will grind into the paint.

Keeping the bikes steady is a matter of securing the rack and the bikes down properly. After you load the bikes, tighten the lower straps again, as the weight of the bikes will pull the rack down, tightening the upper straps and loosening the lower straps.

Thanks all for your comments much appreciated. Griff

I used a super cheap one in college and currently have a Bell 2-bike model now. No issues with either of them, especially with a single bike on them. The key, as stated above, really is getting the straps good and tight - tighten them again after the bike is on it; and having a clean surface on the car and clean pads on the rack. Even a thin layer of dust between the pads and the car will cause scratches.

I rarely carry more than one bike on mine. If I have multiple bikes, they go in the back of the truck, or on a hitch rack.

CL is often great source for racks.

We drove this Allen rack from California to St. Louis and back, and it worked great (Allen Deluxe Two-Bike, $46):