I tend to listen to CDs that I want to actually experience as albums in the car, since the house listening is all iTunes singles mixes. I didn't listen to much that was new this summer, but these made for good summer driving music:

Rain Dogs - Tom Waits
Plantation Lullabies - Meshell Ndegeocello
Tremendous Efforts - The Sadies
David Gilmour - David Gilmour
Gone Again - Patti Smith
Songs and Other Things - Tom Verlaine
West - Lucinda Williams
Emotional Legs - The Leaving Trains

Plus lots and lots of Bo Diddley, who is so summertime for me. Which makes about as much sense as my conviction that Gun Club and The Vines are fall bands, but there you go.