Where to buy car seats
Always buy your car seats new. These seats are designed to withstand one collision - they should be replaced after any accident, even a small fender bender as any collision can cause cracks or hairline fractures in the seat. As for where to buy - anywhere they are sold!! Toys R Us, Walmart, Target, Amazon, direct from the manufacture - really anywhere!!
Personally, I prefer to go to the store because I like to be able to see and touch what I'm buying before I purchase, but there is no problem purchasing online!