On the Boxster, the calipers mount to the rear of the hub leaving the larger of the pistons as the trailing piston (the brembos have 2 sized pistons). If you do not swap the crossover tube and Bleed nipples to the opposite side of the caliper and then swap car sides, the larger piston will be the LEADING one when mounted in front of the axle. Simple fix. Racers say this could lead to a little pad taper. You'll also need to install some anti-squeal pads as the solid mounting leads to more noise with the Brembos.