As Stl says just leave them under the car. I have the 3500 which works for my Boxster and my 928. Like all of us I am getting older (and am likely further along than the majority here) and the Quickjacks really help.
I like the 3500 as it is the smallest and lightest, but it is too short to get to the Boxster lift points so I made some extensions that work both on my Boxster and my 928 (also used on my 924S, my girlfriends Yaris etc.)
This thread shows what I built... along with a lot of discussion on the other models and 928s.
https://rennlist.com/forums/928-forum/1064065-quickjack-3500-with-a-928-a.html
Boxster
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