To get the oil tank open on a 72, the passenger door needs to be opened, where there's a release similar to the one on the other side for the rear decklid -- so it's really no easier to get to than the 73 tank.
The better-positioned tank would have stayed forward (in spite of its higher manufacturing cost), except that changes to side-impact legislation forced Porsche to move it back in 73.
It's a shame it didn't stay up ahead, since the forward-mounted tank not only improves the car's weight distribution, but also helps to cool the oil, since it's not sitting right next to the engine and its radiant heat. (Of course, this also means a rear-seat occupant on the passenger side gets a little extra warmth.)
On the last day of the Open Track Challenge, Tyson remembered that we had forgotten to put in half a quart of oil right before one of the last run sessions. So I ran back to the paddock and got some oil. Our competition in the NSX later admitted to being distracted for the following session, since -- to him -- it had looked like we had added some sort of mystery substance to our 'fuel tank' right before the car went out. While he was trying to figure out what we might have put in there, Tyson kept a half a second ahead of him.
