My custom chin spoiler is higher than about 75% of the bumper blocks out there, and does not catch the snow on the road, no matter how much has fallen. I really think for the effort given, that it is your best deal.
Chin Spolier - fast/easy/cheap/effective - Pelican Parts Technical BBS
I've sent the same link to a gentleman which drives a 1998 electric Ford Ranger, bet he extends his range some if he does one.
It saves me about 3 mpg on the highway.