We don't have a Scion, but we have a Thule rack. They're very well regarded as a brand, and we've never had any problem. Ours attaches to the hitch, but we've used it with a number of vehicles and RVs and it's always worked well to keep our bikes and car damage free. And my husband is VERY particular about his bike! Even their simple trunk mount option (which I think would work with a Scion) gets good reviews.
I am on the frugal side but love my Kuat Sherpa rack. It’s not going to win any ultralight awards, but solid quality and I am confident my bikes are not going to fall off.
Another popular one I have seen around a lot is the 1UP bike racks
We have the Hollywood Sport rider for 2" Hitch for our Subaru Outback and Forester. The hitch makes it adaptable to most cars, It can carry up to four bikes if you add the extension. The rack is awesome, easy to load and go. We've had several of the smaller racks that attach to the bumper or trunk, but this beats them all.