[Subaruwagon]

I am new to ecomodding and have been very happy with just changing my driving habits by watching my scanguage going from 21mpg to about 28 now in my 04 Subaru Outback wagon 2.5 5mt, I have removed my roof rack cross bars, used packing tape to cover the grill, fog light holes, and half the bumper mouth, my tires are about 6psi over the door sticker. I was wondering if anyone had any more tips for mods that would be good for my car nothing too drastic like a boat tail but I was looking at smooth wheel covers and belly pans. Any suggestions and types of gains expected would be helpful.