I built my rack out of 3/4" PVC and used heavy duty magnets (each one supports 65lbs) to attach it to the roof. The yellow tanks & green storage tube weighs it down enough that you dont have to worry about it flying off. I dont take it on the highway though, just local driving up to 45mph.
That’s a pretty nice setup indeed, but… magnets? Seriously? The police would straight away, BURN my licence right before my eyes (for reasons), if they’d wave me over with something like that magneted to the roof (no matter how strong), moving around on actual streets im my country… i’d **strongly **advise to …“reconsider”
if you want it to be more highway speed usable than magnets, illsecond what theodric said but add an idea for installation. permanently install about 3 or 4 inch squarepipe tall studs to ur roof that the box legs will slide down onto. have a hole through it and thread a bolt through each one. ive seen setups that looked similar to that, its been so long that im not sure if thats exactly what theyve done or just similar, but thatd still work pretty well id imagine. ive had the same want for a removable rack as you do, enclosed trailers arent usually that tall. good luck!
Those orange LED/rotating beacon lights in your local Walmart/auto supply store are attached with heavy duty magnets. But I live in the states. Also, I think I’d rather take my chances with the industrial magnets rather than a roof rack you can attach with suction cups that you can buy off the shelf.
