I feel your pain, and having installed these expensive euroheadlights, bought new, on two cars (the moderate cost DJAuto on one, and the very expensive Cibie/Volvo brand on another), getting a cracked headlight is what I thought about first, living in NJ with such really broken up roads as well as full of dump trucks (violating state rules) without covers over their loads.

Anyway, I got those adhesive protective films (somewhat spongy), really thick, and put them on over the lenses. Over the past seven years, I don't have any damage on them (while my hood's leading edge, and the metal just under the headlights, both reveal the onslaught from which the headlights have been saved. Bottom line -- this stuff really works.

It also fools the state inspectors (the covers are technically illegal but they've never noticed them); has yet to turn yellow (another concern unfounded); and doesn't really get any dirtier with salt/slush on a winter drive.

The only downside is that I had originally gotten some headlight wipers to accompany the euroheadlights, but (after all these years) still haven't installed them because I think that the wiper action might abrade the films (especially with salty crud in winter). So I use a mild silicone spray (like I use on my snow shovels and snow blower) to make the crud slide off when I know it's going to snow.