Just bought the Swingbase and the Topshelf. This is a great system no doubt. I love to hunt, fish, snowboard, and get out into the mountains. Obviously, a modular system like this one preferred to address all of the needs of those activities. The one big drawback with this system is security. The two bolts that secure the Swing Base itself to the tongue mount are not locked, so anyone wandering around with a 24m socket wrench can essentially pop off the most expensive part of the assembly (the swing base itself). I talked to Yakima and asked if there were any solutions this problem, they pretty much told me there are none.
So, I went to the local hardware store and got myself two M14 10.9 Hex Bolts that are a half inch longer than the factory bolts Yakima sends. I took those and drilled two holes in the ends of them where I plan to do the following:
1. Weld a steel rod through the end of the screw. This serves a dual purpose as it will prevent someone from removing the nut from the bolt and it will prevent the nut from coming loose due to the constant vibration from the road.
2. Use a reinforced padlock instead which will also address what I noted above.
All you need to do this is some oil, a vice, and a drill bit. Make sure you screw a nut at the bottom of the threading before drilling the hole so that after the hole is drilled, the nut can rethread over the hole accordingly. The rethreading is done by simply unscrewing the nut. Make sure you get a replacement nut as the one you use to rethread is likely toast. Further, this does not compromise any of the factory parts that come with the system so it's hard for me to believe this will void the warranty. MAKE SURE THE BOLT IS RATED 10.9 AND IS MEANT FOR OUTDOOR USE! Also, use Loctite and get a Nylon Locknut :).
@Yakima: Please consider the security concerns of your customers of this otherwise genius system!