We had the same issue. You can spend thousands on a specialty kayak/bike hitch rack. Or you can do as we have done. We sold our kayaks and purchased inflatables. My wife wanted to go back to a stand up paddle board. So we opted for one of those from Sea Eagle and I purchased a two seater kayak from Sea Eagle. They fold up into a bag and we won't have storage issues.
Brian
2013 Thor Chateau 31L