I use bike racks as little as possible. Instead, I buy cars with interiors that allow me to keep my bike inside the vehicle is there is any chance I will be leaving my car for more than a minute or two. When your bike is inside the car it is protected from the elements. A few years ago I did a 1500 km trip from Montreal to North Carolina. WE transported 2 road bikes and sufficient luggage for a week inside a 2003 Volkswagen Passat 4 door sedan. We had to make a couple of overnight stops. I would not even think about using a bike rack for a trip like that. On the return trip, we drove for at least 10 hours in driving rain. I have a hitch rack on my current car, I use it when I have ridden my mountain bike on muddy trails