[salguod]

Depending on what your going to carry, I'd look at aftermarket crossbars from Yakima or Thule. The factory cross bars have long plastic ends on them that limit the usable length of the bars by ~8". My 2010 rack is different than your 2008, but I think they both have this problem. I use mine primarily for carrying bikes when we go camping, and getting 4 bikes up there is real tight with the factory bars. I wish I had gone aftermarket now.

Factory bars are ~$200 a pair, list. An aftermarket set up I think will be about $250-$300.

Here's 4 bikes on the roof of my 2010 with the factory bars:

 

[salguod]

I take them off. It's my understanding that they take off 1-2 MPG on the highway, which is one reason manufacturers give you the raill but not the bars.

The way the rack for the 2010 works, I can take the bars with the 4 bike rack off in one piece & hang it on my garage wall. It's a lot easier than removing the bike racks themselves. The rack for the 2007-2009 is different and that may not be possible.