if you have the money, roof rack... but they will set you back compared to a truck/hitch...and as stated before spend the money and get lock-cores...
personally I have one fork (steelhead) and one crank arm (ankle biter), I do not like the ankle biter, I have NEVER put my road bike on it (carbon crank) but I did put my SS MTB on it, it is nice that you dont have to take the front wheel off, but it just does not seem to be as stable and honestly it is more difficult to put the bike on b/c you have to hold the bike upride with one hand, while with the other spin the crank arm around and lock it to the racks arm...if you do it wrong the bike will come down on top of you...or the other way on to the roof of the car (I dont know which one is worse)