if you go with thule, go with the square rack. this will allow for you to use a yakima mounting hardware too.
yakima's are round but the mounts are made so if you have a square bar, you can just cut off some extra plastic on the mounts to use for a thule rack. thought that was smart of yakima to do.
also if you look on c.l. for yakima racks you can find some good deals. i got mine from c.l. for around $50, the mako and the hully rollers.
i have mine mounted to a honda crv, your outback is going to look big compared to your aveo.
