After seeing a small release of coolant on a short drive, I found the Boxster had a pin-hole leak CRAP! Oh well, thats the car hobby...it's either drive 'em or fix 'em.
Step one, remove front bumner cover to get at the rads....
With the cover off you can see the years of dirt and debris that gets stuck in behind....
It's like a prairie natural museum in here...
The one one the left - behind the AC condenser was the one giving me the problems...
Due to the pin-hole (?) leak, debri had been collecting and turning into mud....which would have been blocking the cooling ability of the rad as well.
Getting the rad out wasn't too much of an issue. One the fender skirt and cover where removed and the hose clamps loosened off, 3 bolts holds its frame to the main inner structure. Then it's just upper and lower rad hoses, a vent hose and the fan wire. I recommend applying wd40 or similar to loosen the hoses from the piping.
Here's the rad from behind out of the car and on the floor...