I backed into the drive (nose uphill) to park on a reasonably clean surface (the lane is covered cr4p from the gasman's diggings) and put the suspension on High. Looking underneath, the little hatch in the undertray had come unlatched and dropped down. I have only opened it once - only to conclude that it's far easier to take the undertray off to change the oil and filter. A pale brown scrape on the undertray right next to the hatch latch suggested that one of the many bits of broken stick in the lane had neatly flicked the latch open.
To add to my fury, by reversing into the drive, I caused the hatch to neatly snag on the dropped curb, folding it at the crease and almost breaking it in two so it would no longer stay latched in place. The only quick fix was to tear it off at the fold; making another little job - next time the undertray is off. If only I'd not been so 'clever' and just driven in forwards!
So if you hear a nasty scraping noise from underneath at low speed, investigate BEFORE you reverse!
