In my case, I drilled a hole in the roof and bought an extra long glow starter - problem solved AND if you drill it just right you really can't notice it that much!
As far as a fuel opening - I was advised to make it as small as possible and mine is probably 1.5" x 2". AND, I have heard a couple of complaints about getting fuel properly 'loaded' from folks nice enough to pit me. BUT, I have it on good authority that a very small opening works better on these cars from an aeodynamic point of view - creating more downforce on the front! So, I consider the extra bit of spilled fuel a necessary by product of aerodynamics!!!
