I picked up an 8x4 foot panel of coroplast at my local plastic supply store to fix up some of the more problematic areas of our volvo 850 wagon 5 speed. This car left the factory with an ok .32 Cd which is surprising considering the boxy styling. Still much better than the .36 for the Volvo 960 and .38 for the volvo 740 and 240 wagons. The whole job took about 3 hours of labor, a couple of bags of zip ties, 3 bolts from home depot and one ruined pair of pants. Total cost was $25. I'm sure it could be done much more cheaply if I went dumpster diving behind Kinkos or Home Depot.
Left front before
After
Right front before
After
Center front section
Rear before
After
My all time best tank without the undertray was 32mpg using a lot of effort to coast and control speed. So far with the undertray we've only done one 40 mile highway trip with cruise control set at 65mph. The trip computer showed 33.5mpg. We'll see how it pans out on our 1700 road trip to Seattle next week.
cheers
Justin