Where I live, there was a rash of smash'n'grab jobs (primarily against women) in traffic jams. Thieves would drive up on a motorcycle, hammer the window, and grab the purse on the seat. Since the victim was on a traffic jam, the bike could get away rather easily while the victim was helpless.
As a result, a vendor began importing film that can be applied to car windows to protect against such smash jobs. The film doesn't keep the glass from breaking, but instead keeps holding it together making it very very hard to actually make it PAST the glass in a short amount of time. Thus, the effect of the "smash" part of the operation is broken: smashing the glass is not enough to make it past it. And obviously you're concerned about protecting the data and the time and effort lost if the laptop is stolen, so an investment in this sort of passive protection system might be warranted - even if you throw in the price of a new (set of) window(s).
This is an example of just such a technology. I'm sure there are others and more than likely at a better price. The flipside is that in the event of an accident, it might increase the chances of injury (just a guess), or delay emergency personnel from prying your damaged laptop from your cold, dead fingers.