So, I bought a Yakima hitch rack a few months ago and recently bought a car topper as well. Maybe I’m missing something, but the keys for the car topper also open the hitch locks and vice versa. What good is having a lock if every Yakima key can open any Yakima lock? Is this why they sell locks separate, so that you spend the money to buy new locks?
The keys have numbers on them; if you buy more locks and the numbers on the keys match, they will open those locks. So not all Yakima keys will open all Yakima locks, but some will. I am not sure how many different “number” keys/locks they produce, but if your current key works both your locks, I’d consider yourself fortunate.