Greetings esteemed Boxster Lovers... 
I've got a 2000 Boxster 2.7 w Tiptronic - my BABY... purchased used in summer 2010 after a 10 year love affair with my first porsche resto project - a 1968 Porsche 912 4-speed manual that I raced in SCCA and PCA here in Chicagoland... 
After I took my 2000 Boxster out of storage last month, I noticed the alternator struggling to keep the lights on at night, and suspected the serpentine/drive belt needed to be replaced. 
This forum & some great Youtube videos (thanks Graham White!) convinced me this was not only do-able... it was EASY. a 10 mm socket wrench and a 24 mm socket on a breaker bar, and I was ready to rock & roll... 
Everything went smoothly at first: 
- the seats stayed in (NO need to take out passenger seat as many do)...
- the soft top unsnapped and slid forward in under 2 minutes... 
- the oddments tray came off with 2 twists of a wrist... 
- the top cover (actually unnecessary) came with 6 twists of a wrist... 
- the 4 carpet hold-downs came off by hand (2 with just a little coaxing)... 
- the 8 10 mm access panel bolts came off with a full wrenchturn + wrist... 
Then I gently pryed open the access panel (watch those edges are SHARP)...
... and saw a complete serpentine belt !
:-O
A closer inspection revealed 2 things: 
1. The serpentine belt WAS indeed complete, but 2 of the 6 (or so) "grooves" had actually SHREDDED COMPLETELY OFF, and were snarled all around the engine bay in what looked like black spaghetti; and 
2. The entire alternator and its wheel were NOT ALIGNED with the rest of the 6 or so drive wheels !!!
Still closer inspection revealed that the lower alternator mounting flange - basically a bolt hole on what looks like a cast aluminum plate which bolted onto the front of the engine, provided a mounting point for the alternator AND some sort of fluid entry nipple for some flud circuit in the engine - was completely BROKEN OFF... 
 
THERE'S STUFF I DON'T KNOW: 
1. WHAT do I CALL this part? 
2. WHAT is the fluid system behind this plate (coolant or oil or trans)? 
3. CAN I simply replace this single plate (approx 2" x 6" with 6 approx 8mm bolts running through it, a 3/4" OD nipple on the left hand side as you look from the front, and just above that the mounting hole for the alternator mount bolt) ? 
4. WHERE do I go for a decent used part (I've always only gone to German Auto Dismantlers, but now I hear they've been sold, and I don't know what the new owners are like)? 
5. DO I have to drain whatever fluid is INSIDE this plate? 
6. WHAT is a FAIR price for a used whatever-this-is part? 
Thanks to all for a prompt reply. 
Cheers, 
-Mark