[fragdude]

If I was to want to take up your kind offer would it be something that could be done over the net or would it be the kind of "I pay the postage" sort of thing?

I'm pretty sure we could work it out either way...I have them electronically, would just need some way to send them.

Any idea what 4,000 rpm works out to in mph in each gear?

I downloaded the 2007 Boxster Manual (its amazing whats available online!), and being porsche they put the gear ratios in it. Unfortunately, they no longer have the speed to rpm chart for each gear like they used to. But I worked it out using a speed vs rpm calculator (assuming the loaded tire size is 19 inches, which may be too small, and the 5 speed transmission) to this:
1st gear: 34.5 mph @4k rpm
2nd gear: 56.9 mph @4k rpm
3rd gear: 84.3 mph @4k rpm
4th gear: 110.6 mph @4k rpm
5th gear: 143.6 mph @4k rpm (althought I think for the break in period you shouldn't go that fast )

The manual is available at:
http://www.analogstereo.com/pdf/om/porsche_boxster_owners_manual_2007.pdf
(or pm with your email if you want me to send it to you)

and the calculator i used is at:
http://wahiduddin.net/calc/calc_speed_rpm.htm