For those of you who only have the car seat but no stroller - there's a solution. I came across this on amazon just now & thought I'd share:
Also came across this option, which is more versatile & compatible with many other brands:
http://www.overstock.com/Baby/Contours-Options-3-Wheeler-Stroller-in-Blush/5698854/product.html
I think I'm gonna go with the contours