[Wobblybob]

I saw somewhere that Volvo once had a retractable air dam and saw some patent application drawings for something similar.

How about us DIYers? Has anyone done this?

The major disadvantage of low air dams seems to be damage in parking lots and their extreme (read geeky) appearance in low speed environments and their major advantage doesn't kick in 'til you get up to speed (what - over 35mph?).

So why not make them retractable for slow speed areas and extendable for higher speed areas? Best of both worlds.

Is anybody doing this? And if not, why not?