Alright, I got my Thule racks setup on my new Vibe! (hopefully this is the right place to post this, apologies if it isn't)
Having a full, large set of racks on my car is a must or me. I do a lot of canoeing, mountain biking, and skiing and being able to carry stuff on the car makes for happy passengers. I have used this Thule rack with minor modifications on many vehicles over the past 7 years or so, and was very glad to continue using it.
The Vibe was a bit of a challenge to get worked out for mounting, but not impossible. I pieced together a bit of info from a couple different threads on here and various (luckily not out of date) information from some retailers pages. I'll list the details of what I used here in case others want to replicate.
Here is a picture of the car with the full racks on it:
For the front I used a pair of Thule 400xt aero feet with the fitkit #2119. Listed as the fitkit for for the Toyota Matrix/Pontiac vibe. The kit comes with front and back fit kit pieces. The shorter clamps go in the front. I had the aero feet already, but you can find them on eBay/Amazon pretty easily. I found the fitkit (which is discontinued), brand new for $25 on ebay.
For the back I used two crossroad 450 feet, these mount directly to the factory rack on the Vibe. again I found these on eBay for really cheap--$45 for the pair (they were missing the covers, but replacement parts for almost all Thule products are easy to get and fairly inexpensive. I've had very good luck using the site etrailer to get parts). You can also buy the feet new in a two pack that goes by the item number 4502 and coats $120.
These both attach to the 65" square bars that I already have.
Altogether I spent about $90 to get everything. If you wanted to recreate this from scratch with brand new parts it would be quite expensive, but through some careful eBay hunting and maybe local Craigslist parsing for used crossbars I bet you could reproduce this pretty easily.
Here is picture of the Vibe loaded up with my old Gazelle canoe. Handled the boat like a dream. Drove 3+ hours like this, including some 65 mph highway time and felt totally stable the whole time.
This does leave the front bar about 1in higher from level then the back bar, but functionally I don't think this will be an issue at all. If anyone wants detailed pictures of the feet installed let me know.