08 Impreza Twin Exit Backbox08 Twin Exit Backbox. This is done in the same style as the rally car, one round one either side various sizes but you will need the new Centre pipe (listed below) as we have had to put the join in a different place to enable smooth flowing pipes to each side. Standard tailpipes 2 x 4" slash cut. If different design required please ring. To fit models 2008 onwards Available in 2. 5" and 3" pipework