Tips for proper jacks + accessories for work under heavy saloon

Good evening, I won’t be able to use a lift as much as I like in the future. Since I like to screw myself to my car (Mercedes S-Class) from time to time, I have been thinking for a few days about how I can set up for work under the car in the future. Since I can only work outside in a parking lot, maximum in an underground car park, only a jack with extras such as underhangs is in question. ts this cheap jack from Deuber. The thing is nice low (I absolutely need) and suitable for up to 2T but I don’t want to lift a complete axle with the thing for a long time and also put myself under the car. At the moment I can’t get any further. Thanks to the sports package and air suspension from factory, the car is quite deep and completely disguised from below. I don’t know a recording point per axle. Now I am on this set from Bahco consisting of 50kg jack My idea would be, for example, to lift the rear at the lifting points under the doors with the cross beam at the same time and to place the lower beam at the front. Unfortunately, the cross beam with a maximum width of 98cm is apparently not made for it. Unfortunately, I can’t find a cross beam that is at least 1.60m wide. Do you have better ideas for a quick-up and degradable solution? Otherwise, I have to use a proper jack (the top ve However, it’s too difficult for me to buy a jlinkte from Bahco) and if there is no other way to go to a rental workshop with a lift.