I have a trunk mounted bike rack and i hate it. I feel like the bikes are going to fall off at every turn. Roof racks are expensive but they are worth the money for that extra security. You also got tow hitch bike racks but i have zero experience with those.
As someone that had a rack on the back of their car, I could secure it, but I don't like the marks it left on my last car.
As I get my focus, I think I am going to go for the trailer hitch and rear bike rack - less aero drag when you're not carrying something (as the bike carrier isn't installed, but the bars and rails up top are always installed), and you have the option to add a small trailer for a kayak, canoe, or platform for a cooler.
But I am open to hearing that on top is better for some reason.
I have a Yakima KingJoe 3 for my other car and while I do like it, I'd much rather have a roof rack. I had to settle for the trunk mount because finding a roof rack for a 7th-gen Celica is nigh impossible, and the one or two that are out there are obscenely expensive.
That being said, I was initially concerned about how secure my bike was on the back but as long as you set it up properly, it really is a secure setup. I can grab on to the Yakima and literally move the car up and down and side to side without the rack shifting or coming loose, and I use the included nylon straps to help secure the bike to the mount.
For every day driving you won't really notice an effect on handling, but with a tail happy car like the ST I'd be a little concerned with having a 20lb or more counterweight hanging 1-2 feet behind the car if you were doing any spirited driving. Might be fine but I don't want to be the guinea pig, you know?
I have a Curt above-exhaust hitch and a 1-1/4 inch cargo carrier from Walmart. I notice no difference with the hitch, though to be transparent I did a spare tire delete so the difference is offset. I have carried up to 200 lbs on the cargo carrier with no noticeable difference in handling, just a slightly softer ride in back. Kind of like when I put my daughter's huge 9 and 11 year old kids in the back. Have to say I don't thrash it with all that weight back there but use your better judgment and you should be fine.
Oh, and I have carried the bike back there as well by using ratchet straps. It's only fallen off twice!
I don't race around with a bike on my car. I like a trailer mount rack best. I wouldn't want a muddy M-B on my roof. I also think it would be hard to lift a 35lb bike on the roof after a ride. Last year I crashed my bike and was hurt. I had trouble lifting my bike on the rear rack I was in so much pain. The one thing I don't like about rear racks is the wheels block the brakelites so I mounted some trailer brake lites on my rack. Sweet
So instead of burning through extra money for a bike rack for my FoST, I decided to try the Thule rack that I bought for my 2002 Honda Si hatch first. It is a two bike rear mount rack bought years ago. With some adjustments of the previous Honda setup, it seems to work fine for the FoST. Albeit, with the exaggerated angle of the FoST hatch versus the Honda, it is now a 1 bike solution rather than a 2 bike carrier.
The price point of the latter seems much more in line with what I have. As mentioned, from the Honda to the FoST, I had to open up the mounting points and because of the increased slope of the FoST hatch, it seems only one bike will fit without some damage to the hatch.
Hopefully this weekend, I can post some photos to show.