I've got you beat so far on the leaves - 35 jam packed big bags of leaves.

There was a switch like that on the M41 I put in my PV. The 4th gear switch mounted to the top of the cover, and was actuated by the 3rd/4th gear selector rod, and the reverse light was on the rear and grounded against the reverse selector rod. But there was the 3rd swith built into the extension for the remote shifter - and was actuated whenever any gear was engaged (I didn't notice if it didn't engage for reverse) by a ramped thread spool shaped doohickey mounted on the remote gear selector rod. I too have no clue what it did, perhaps I'll look on the microfiche at www.gcp.se to see what they call it.

Edit - Charming - I found the switch but the parts microfiche refers to #39 and #40 as "Two contact switch" and "Three contact switch". Beats me - I guess you'd have to look on a wiring diagram to see. I didn't see the switch in the B20 1800 listing, only in the 140 series listing. Perhaps it has something to do with the seat belt buzzers/lights?