Originally Posted by
indyfabz
You can always get a cheap, plastic tarp from Walmart or an Army Navy Store for some protection from the elements. Bungee cords attached to the grommets to keep it in place.
I would be a little worried about a tarp (and even the bungee cords themselves) flapping around at highway speeds. If it flaps against the bike or car, it'll damage the finish pretty quickly.
This dilemma is the main reason why, when we buy a new car, we always choose something that will hold a bicycle and cargo. The car need not be that large: our 2007 Honda Fit looked tiny, but it would hold a bike, tools, spare wheelset, luggage, and the three of us for a weekend trip to a bike race. It was a little tight, but it worked -- and it got about 38 mpg on the interstate.