dont have a boxster..but a 1984 alfa romeo spider..have 12.19 vented disk on all 4 corners, and brembo calipers from a 2000 boxster on the car now.. a very nice upgrade.... i am using a 2000 boxster brake master cly on the car..no booster..( no room )i have not drvin a boxster.. by all the brake tech i have read.. it should work.. car weighs 2380 pounds..any thoughts here? thanks