.... you know, those covers that go over your handlebars, shifters, fork, and stretch back over your seat... for use when your bike is forkmounted on top of your car. I am getting ready to transport my bike on my roof rack for a 200+ mile trip on the interstate. I wonder if using one of these things would provide at least a little protection from the elements and road trash. Or are they like sails that significantly reduce gas mileage???

Thanks for your help!!!