The guys at outfront motorsports have been hotrodding subies forever and they sell shortened pans that are just cut off for ground clearance. They say to run the oil higher in the pan no problems with sand buggies and street cars don't do near the stuff buggies do. Also I never had a problem jacking the car up more on one side to completely drain the oil if thats what it takes. For a bigger oil filter you can use a honda s2000 filter, it is a lot bigger. When my sons sti was stock it would need oil added at about 2500 miles, mobil 1 5w30. On changes I wanted to put the whole 5qts in but he didn't want to do that. So it would need oil sooner.