My 1 y.o. +4 was in for servicing yesterday, and the workshop guys noticed that it appeared low on the driver's side - on checking, the gap between the top of the tyre and the lip of the wheel arch was less on the driver's side than on the passenger side...further checking showed that it's like this on pretty much ALL of them, to a greater or lesser extent, even brand new cars!

Anyone know what the cause is, or the cure, if there is one?

It's hard to say without more measuring. On level ground the chassis rails at the rear axle point should be equidistant from the ground, but if they're not, the reason might be the front suspension. So to find the truth will take a bit of time. There's been another thread on this subject. Where the engine rotates clockwise viewed from the front hard acceleration will twist the car in the opposite direction, so clockwise viewed from the drivers seat. So the nearside rear will squat more than the offside rear, and that's why dragsters using this layout will lift the front nearside wheel. Eventually the spring will sag on the offside rear and give a lean. The cure is trial & error. A new rear spring might level it up, but my experience of leaf springs on MG's is that they vary considerably in camber from new. So if you were to try a new rear spring and that doesn't level it, The problem may be at the front, and so it goes on. I remember once building up two leaf springs from four donors when none were a good match. Ridiculous but true.

Less than two years old - surely any variance in the springs is a warranty issue?

As sort of said earlier, the body to tyre distance is not a reference one should use. Measuring distances related to Morgan bodies is doomed to give odd results - coachbuilt bodies and all that.

Measuring chassis height on flat ground ought to be more reliable. Not unknown for any car to sag a bit on the drivers side as the driver's seat is always occupied. But since most roads are cambered, only the really observant would notice.

Thanks for the tech bit, perfectly logical, but the point I was making was that ALL the cars in the workshop & showroom that were reasonably similar had exactly the same thing!

It's all to do with the rotation of the earth, the camber is to offset the Coriolis forces acting on the chassis when cornering at speed. Cars ordered for delivery in the Southern hemisphere e.g. Australia, New Zealand have the sag built in on the opposite side.

Actually the Coriolis effect is why driving on the left in the Northern Hemisphere is a good way of stopping whirlwinds.

It's to allow for when the wife's in with you.

Even the Bronze raffle 4/4 had the rear offside sagging! Mine does but it handles fine so I'm not bothered about getting it fixed...it will only sag again!

Try to get one that is low on the passenger side, then it wil be level when you drive it solo.