Perfectlap,
Attached are dyno charts from Evolution MotorSports for the Air intake and Chip/Intake upgrade. I did several months of research and inquired with a number of Boxster owners who did the Air intake before putting down the $400.
According to the charts, there is actually 11hp increase to the wheel with just the the air intake. I guess we can also argue that the dyno's are fake and it's all B.S. since it's Evo who makes the intake.
Also, check previous thread
stock h.p at the wheels. He dyno 246hp to the wheel (almost 280hp) after headers, chip and air intake.
Aside from numbers, I think what really matters is how it feels. As long as it makes me smile a little more driving the car, it doesn't matter if it actually adds 2hp or 20hp.
I agree with most Boxster owners that the car is great as is, but a little icing on a great cake always makes it taste a little better.
With regards to the tires, I didn't mean to offend your opinion. I was referring to R compound tires as an upgrade.
P.S. I didn't mean to stick all the numbers at you, but I can't help myself since I'm an Accountant and I use to be an auditor!