[lunarhighway]

gillblock, full or partially, seems the best thing to start with.

an undertray might be a better and even less visible alternative to an airdam extention and not that difficult to make.

i'm curently running a warm air intake that mixes warm air with the normal air.

it works great for economy but it does reduce top power, so that mod might work for a "bigger" engine

personally with your commute i'd go for the most aerodynamic car you can find with a tall gearing. even if it's a little heavier or hasn't got the smalles engine. (all relative)

what sort of milage would you like to achieve?