"We don't undercoat those areas because...." ??
My 89' VW Jetta was factory undercoated below the doors at Wolfsburg - then it was painted over in the body color. This protected area was nearly invisible when looking at the car. After 25 yrs on salty Ohio roads - that area never rusted.
Saw this stuff for sale - genuine VW product.

Has any major Vespa dealer ever posed this question to Vespa?
It certainly wouldn't add much to the purchase price to have that stuff shot under there before painting.
O.S.
