Book early with Hertz and you can get up to 25% Off. Book 60 days in advance to get 25% Off ~ Book 30 days in advance and you'll get 20% Off !
Hertz Advance is available in the UK, France, Italy, Germany, Spain, Belgium, Netherlands, Switzerland, Luxembourg and Norway.
Plus they also have some good student offers which mean they can get 15% off car hire and 20% off van hire.
It seems a good deal for older students as A Young Driver Surcharge is applicable for students aged between 19 and 24.