Those rooftop tents are a great idea but the pricing is a joke. $1500 for a tent? W.T.F.
You could build your own platform for the roof and buy a decent quality tent for less than $400. 3 season tents are not expensive. 4 season expedition tents are like $300 - $500 but you're are talking about camping in high wind, below zero temps at that point
It looks like most platforms open up with the tent stuffed inside it. You would then set up the tent right on top of the truck. Why not make your own? Sure it would be heavier but I don't think it would be a deal breaker. If you already have a tent then just use that on top of a platform.
2 sheets of plywood w heavy duty hinges bolted to a sturdy roof rack. wrap it in a tarp then use racheting straps to keep it secured for the drive.
Upon arrival open up platform and set up your tent on top. fix a few eye bolts right to the plywood for the guy lines. That'll keep the tent from blowing away. You could also secure a tarp to this to act as an awning (use the one that wrapped up the platform)
have two legs that reach to the ground that attach to the overhanging platform for support.
find a ladder from a pool or something to get you to the top of your car easily.
Yes it may sound ghetto but it could be made to look clean.
Tents are not expensive. It seems there is a huge markup for the 4x4 crowd to put a tent onto the roof of a vehicle. But if you have the money to spare then why the hell not. It's easier than making one. As a longtime backpacker I know what the cost of a tent is and I cannot justify the cost for a rooftop.
Just sayin
...and then there's this thing
Stuff, and Things: The Eezi-Awn Bat 270 Degree Awning
$1200 for an awning that can't handle wind. A tarp, rope and a few poles can be had for like $70, spend the rest on hookers and blow...or tires and a tuneup.
end rant