Yes, they squirt every fourth activation of the windshield washers. There is no independent activation. The best way to verify is to be driving at night (or sitting in front of your garage door) and then hit the wash button for 1+ sec 4 to five times. You will see a noticeable impact on the headlight projection when the lenses get hit with the wash water.
Are you asking whether or not you should/could have them?
Here in the US your freindly neighborhood stealership can "enable" them through the proper application of his StarScan tool.
I got mine "enabled" back in October of 2005 for (1) Havana cigar to the service manager who did it as an experiment by himself to see if he could do it, and I didn't even buy the car from his employer! Nice guy. My selling-stealership tried, but failed
Other owners have supplied pizza for the stealership's shop as thanks.
Yet others have been forced to pay real money for the stealership's shop time.
Any stealership worth their 5-stars (even some that yet haven't attained that lofty status) should be able to do it. All that's left to determine is the price!
Do a search on this forum, you'll find complete directions to hand to the less-enlightened stealership to set them on the right path.
Funny story...not 300 related but head light washer related...My buddy has an 01 Audi S4, so he asks me what the little bumps in the bumpers are in front of the head lights??? so i tell him that those are your head light lenses washers...he says what??? no way stop messing with me and hes laughing like im joking, so i say ok get out and go watch your head lights...so i get in the car hold down the washer button for the wipers, out pop the light squirters and spray down the lights, my boys face dropped with disbelief he started to laugh uncontrollably and had to leave b/c he was astonished over the fact that he had lenses washers, so needless to say thats his new toy now he just likes to drive around and spray down his head lamps for no reason, just b/c he can, now he goes through washer fluid like a champ, i never knew head light washers could be so amusing to some people...LOL