Op-- not sure how far away from a Babies R Us/Toys R Us...but they allow you to take floor models out to your car to test fit. Believe it or not...this is extremely common. Heck with baby number 3 we had to test fit 3 seats to get one that fit properly in my wife's HUGE minivan!
The trend today is large car seats. The more expensive you get up the price chain the harder they are to fit. Just figure it is a short term problem as they go forward facing by year one and they fit the car better.