GM has been using similar airdams on many of its cars since the '80s.
An occasional scrape is part of life and it always lets you know where
the concrete block is on a diagonal parking place before you screw up
something expensive.  Sorry about the crossmember.  I hit a steel truck
bumper @ 65 mph with the C4 last week and made out better.  Just a front
end alignment and a new right front tire.

I think the C5 airdam is an improvement over what we had on the C4 as
the low speed cooling on the C5 seems better than the C4.  I'd put it on
the checklist of things to have done--might save you an alternator.  As
Bob Ireland says, cross the big dips at an angle.

The mount for the air dam is removable/replaceable, part number
10400765 and costs $148.69 plus shipping. It is also repairable by
most any bodyshop/muffler mangler or someone that wants to get out and
under. It is held on by 4 bolts but it obviously is not were you can
pick it up and put the new one on without some additional work. Never
are the parts you want to replace on the top of the car waiting for
you to brush them off and lay the new one down. It is relatively thin
wall square tubing and could be pulled into shape using a h0ome made
puller with a 2X4 and a cross "J" bolt through a hole drilled through
the 4" (actually 3.5") direction to pull it back in fair shape.  I'm
sure I could change or repair it in less than an hour but then I have
the tools and a lift to do it the easy way.

No, the front end does not have to come off, maybe some skirting
underneath but not much. It takes 6 and 8MM bolts, small and easy to
work with.

Bob G,

You need a 1998 manual, all three books and I'll throw in a CD
assembly manual for $65 shipped? Some greasy finger prints already
installed and a dog ear here and there but it's still a very
serviceable set. They are the full version, not the preliminary set.