FWD Roadracer fuel cell placement?

We have a Volvo C30 car that we race in the ChampCar Endurance Series. Or should I say that we are rebuilding it after I stuffed it in the wall. 

Since we are in rebuild mode, I am thinking (or overthinking) the placement of the fuel cell. Like many FWD cars, the rear tires are close to the rear bumper so it doesn't leave much room to put a cell behind the read axel. That being said, we had a wedge shaped 18 gal. Cell fitted over and behind the axel. Now for the rebuild, I'm thinking over and in front of the axel (more in stock position).

My question is this .... is the advantage of rear weight percentage with a possibility of a pendulum effect of the fuel behind the axel a better choice than giving up some rear percentage but having all of the fuel rearward, but still between the axel?

It wasn't too bad behind the axel, but just wondering about what is "the best" place.

Also, if by some strange reason that ypu can get a 50/50 front to rear weight in a FWD, is that really a good thing?

Thanks

Personally, for an endurance car, where it's more about pounding-out lap after lap consistently, as opposed to an outright blistering lap, i would want the fuel as centrally located as possible.  To me, this would maintain a closer balance as you burn fuel through a stint.  Let's say you have a 22 gallon cell, in a 2600 car.  With a cell closer to the rear of the car, that's roughly 20% of your weight behind the rear axle at the start of the stint.  Much less so as the fuel burns-off. 

In reply to grafmiata :

Yeah that's kind of where my thoughts were going.