I’ve used the scissor jack when my rear drive pegs fell out and then the knock off undid itself. It works fine, just makes sure it is along the area by the seat where the upturn of the fiberglass gives it more strength for lifting. I also use a wide saddle floor jack (Harbor Freight $139 Racing Jack) under the sill without problems, but using a 2x4 or 2x6 to spread the load over a greater area works even better.
The only problem I have had was when I used a 2x4 on a jackstand to support the car under the sill and the 2x4 slipped causing the top of the jackstand to protrude into the car behind the seat. I won’t make that mistake again.
My mechanic jacked the car just behind the front wheel well and just in front of the rear wheel well. He generally put a 2X4 or 4X4 about a foot long to spread the load across the car (i.e. left to right, not front to back).
No damage to the car.
You can also put a scissor jack or floor jack under the outer end of the lower wishbones (there is a short brace running across the wishbones at this point).
I find that the best way to lift the front is to put a same-size wooden batten under the headlamp vacuum reservoir (ie front chassis cross-member) and jack under that so that both front wheels come up together.
The back’s a slightly different kettle of hows-yer-father’s though - if you’re careful it’s OK to place a thick wooden batten under the diff housing mounts and jack on that.
The problem, I’ve found, with jacking the rear of the sill (just in front of the rear wheel) as the manual instructs, is that, whilst it does get the car up, there’s an alarming increase in the gap between the top of the door and the rear bodywork (this is a roadster I’m talking about by the way) clearly demonstrating that the back end of the car is sagging under its own weight - nasty!
The factory worshop manuel lists two methods :
first I assume is to lift a single wheel. For the front, they show the rod at the bottom off the shock.
for the rear it is the outer cross member on the rear a-frame.
supporting all foue wheels off the use boards acroos the bottom of the car roughly at the inside arch of the fenders .
I have used a board a front cross memeber ( prevents the dents you see)
on the rear I sliped the floor jack arm between the exhaust pipe and the frame center section around the front mounting points of the rear a-frame ( i use to have wood block arandment to facilitate) .
when I put my car up for extended periods I tressel the back with a board and jack stands on the out board portons. For the front I place jack stands under the front uprights ( I have never been confortable with the recomended “under the shock stud” the book shows.
I have found that if you can use wood to spread the load you will have more options ( esp on the frame)
My vote, regardless of what the book may say is only lift your Lotus shell when you are removing it!! Think of the load you are putting on bobbins, imagine the crack inducing stresses going through the shell
Lift the car with a sensible jack and a piece of wood either under the vacuum tank/crossmember at the front or the chassis under the diff at the rear. You can still take the weight off the suspension front or rear with a second jack under the suspension if needed.
If you must lift on the wishbones as Steve suggests then do use wood to spread the load, the rear wishbones bend very easily