That is the CVT gearbox, not a robotised manual, so diagnosis and repair is worse than
judderbar suggested.
CVT= Continuously variable transmission
There is a steel belt, running between two pulleys, which can vary in diameter, giving a continuously variable gear ratio. Wonderful when working, frightening if they fail, as there are no repairs to be done, unless you can find a specialist. The manufacturer resisted making parts available, as rebuilding these is very specialist.
The 'L' position causes the box to hold the ratios lower than normal, which is great on steep downhills, fun when accelerating, sometimes useful in slow queues, but noisy and drinks fuel.
'E' as said, causes early upchanges, for economy, not good in busy environments, as following traffic will get angry. Makes little difference to actual fuel used, but does make it sluggish.
Pushing the lever to the left causes the gearbox to select the nearest of 6 pre-set ratios, and when the lever is pushed + or -, causes teh ratio to move to the next of the pre-sets. Fun once, then a waste of time, as the gearbox makes better decisions on its own. Occasionally useful in snow, or slow-moving traffic, where a constant ration is preferable in certain circumstances.
These are getting old now, and nearer death. A low mileage does not mean lots of life left, as lack of use is as bad for them as lots of use. I had one almost new in 2003, loved it, miss it, but wouldn't get another now as it'd be threatening to be a money pit every moment it was operating.
My advice, buy only if it is very cheap, very very cheap indeed, and you can afford to bin it if it breaks. These Mk2s can suffer from rust around the rear of the sills, and the rear subframe mounts and seatbelt mounts, so that needs to be checked too.
There is almost certainly a better car for you, out there somewhere.
