strange you should say that Paul - Ive had my 172 just over a week now and find that the headlights are to low. Mike172sport told me in another message to look for a link between the back axle and a potentiometer - situated on the passenger side just before the back wheel. This is the self adjustment for the xennon lights and you should make sure that it is connected to the axle and not just hanging loose !!
mine is also an import, but then again I thought that they all were ! only difference is Renault have not skinned me for an extra 2K for the fancy forecourt display and the water cooler.
I also took my 172 into Renault on Friday and complained that the beam was low - they said that they put it on the mot tester and they were fine.
They took 2 hours to change the hazzard switch and check the lights - mind you, as the girl on the front desk said "we have cleaned your car sir !" - w**kers
hope any of this helps,
mitch