swen,
I was thinking about the same thing and decided that i am going to just use a regular seatbelt in order to secure the car seat in place. That will also work once my son gets older. My truck is currently getting the seatbelts put in during the painting process. I think that my seat will be VERY tight with a car seat in the middle. My guess is that your front seat is wider.
My 2 cents worth,
Chris