impreza??

Are you talking about replacing the stock seats with something different, or putting in a child car-seat?  Either way, your best bet would be to look around these sites:

http://forums.nasioc.com/forums/forumdisplay.php?f=109

http://www.ultimatesubaru.org/forum/

You'll find everything you need to know and more about the Brat there.

im pretty sure that the impreza seats will fit...know someone who swapped seats, as far as i know they were imprezas