Well, I don't know about roof tents, but I've had the Sport Rack SR1002 for a year and a half for my 2008 Prius and it hasn't flown off and I'm happy with it for carrying ladders, kayak, etc. I wouldn't hesitate putting on a roof box either

https://www.amazon.com/gp/product/B00BHWMDSM/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

The installation took a bit of back and forth adjustment before I dialed it in, because the roof of the Gen 2 Prius is extremely curved. But once it's on it has been very stable.

I chose it base on price for the most part, as the Yakima/Thule were too much for me to spend, and the tower model that had great review were no longer available.

Note on two things:

- It will definitely make indentations on your door rubber gaskets, but that's unavoidable

- You definitely want to periodically check and tighten the clamping feet, because mine loosened up after about a year. I'd thought about putting some locktite on it, but if you check every 3 months as a safety check you should be good.