I run an EF Air box in my car with a RushO2 performance air filter (RRP $100).
I could not notice any difference between this filter and a $7 supercheap auto filter... seriously.
The air box itself has some flow restrictions, so IMO, panel filters are a waste of money unless you sort that out first. On the other hand, its hard to beat a 3" pipe connected to a pod in the wheel arch, thats if you don't mind cutting holes that is.
As for ram air, I think everyone at the last Heathcote meet in melb proved that to be almost useless.
My 2c for the day
Simon