I have the same, small portable hoist as Andres. I know there are others here who also have the max jack.
I purchased a $330, 24’ length of 2.5 x 2’ tube, and 1/4 flat bar.
I removed the max jack inner arms, and replaced them with sections of the 2.5x2 tube with flat bar. I have yet to drill out the hole for the rubber circular feet. I have been using thick rubber for now, until I get the correct diameter heavy wall pipe to accept the feet (not an everyday stock item out here). They will be welded into place.
It fits both elan and +2 perfectly as they reach to the chassis. I feel much safer being underneath now.
Only complaint, is they dont hide away inside the outer arms of the max jack. Though, they are easily removed. Same goes for the max jack when I need more space for a boat or cabinetmaking etc. The max jack is nice because it is removable because the concrete expansion anchors provided are threaded. And I do lift suv’s and light truck fine with it 12 years in.
Having said this. When I built my shop. I reinforced with rebar and other metal around hoist points, so the concrete should be very strong in those areas.
If I did it again, and wasn’t broke. I would spend the $15k on a Challenger or Rotary in ground hoist (and I did dig deep and wide enough, filled with sand if I choose a inground in the future). As the arms hide away. Suppose the real draw back is you dont have a clean/flat floor to roll things on.