Just to update, received the car harness (Dr Foster Smith 9N-3243) a while ago and did a test drive with the dog. Seemed to work pretty well, although I have my doubts as to how well it would hold up in a frontal crash. Some of it is made out of seat belt material, but it uses those cheap plastic buckles you see on backpacks, etc. The dog does slide around quite a bit on corners, I think she needs a racing harness.
Also, got some booties from dozenbooties.com, they seem like they will fit the bill. Beware that these are for sled dogs, so the "small" size is just right for my 70lb German Shepherd.
-james