My 356 seems to sag on one side (driver side 1.2" lower than passenger side. Is this common? Can a tire/suspension shop resolve this? Any help appreciated
Lay off the pasta! Is it a VW pan-based Speedster? Has it always been listing? I'd first check for broken/bent suspension bits. A shock loose/leaking?
If VW - the rear has separate torsion bars on each side that can be adjusted. So lowering the left rear will also raise the front right some. Same for the other side. Some owners use an adjustable aftermarket spring arm to adjust and fine-tune the rear. Check to see if they are there -- as adjustment bolt could have loosened up.
Adjusting the rear is unique to VW (Porsche) - so if you can find a dune buggy shop or VW one - they would know how to adjust the rear. There are You-Tubes on it too. Can be dangerous as the torsion bars are under spring pressure.
The OEM VW front uses an H beam with upper/lower torsion leaves (flat bars) that go side to side. They aren't separately adjustable side to side. A bar or bars could have broken and dropped one side. There usually is a beam adjuster top and bottom (some only 1) that adjusts height of front end --- up or down but not side to side.