Does anyone use a cover for a bike on a car rack? I'm starting to take longer trips to ride in different locations. I thought it might be nice to keep the rain and road spray off the bike while in transit. I'm thinking of something similar to a BBQ grill cover that sinches up at the bottom. I have a Thule platform rack.

Is it even worth messing with? I don't want to be "that guy" driving down the highway with a tarp half off blowing in the wind.

Thoughts?