Car Insurance for an Au Pair

[GreatDadinTraining]

We are about to move from Nanny to an (EU) AP when youngest starts school, and they would mostly be doing school runs and a bit of after school minding. The agency warned when discussing age of the AP that insurance might be a problem with 18yr olds etc, so we're a bit unsure what minimum age to consider (you can get very mature 18 yr olds and immature 21 yr olds, obviously!)
Unfortunately Direct Line don't do theoretical and were unable to give any idea about potential costs for adding an 18 yr old AP to the policy, so I have no idea how significant a factor age is, and how much of a problem this might be.
Anyone any experience on this?
Thanks!
GDIT

I've had AP's over 21 and not had any problems adding them to the insurance. They've all had at least between 1 and 6 years driving experience.

It isn't a problem it is just a huge cost. I insure people under 25 in my business the current one has 5 years no claims bonus drives a 1.4 foucs and best car insurance we could find was £1700 and this is for a veterinary surgeon. One of the issues is that the person mainly driving the car is no the car owner.
What I would invest in is a few driving lessons before your DC go in the car with the AP just to get them used to driving on a different side of the road in a strange country.

you can use a comparison website to check costs by age range quite easily.

IME under 21 is a no-no because of cost. 23 is better than 21. Last time I looked it was cheaper to put them in the category of childcarer rather than student.

If you have a problem with current insurer (some will not touch APs no matter what), try Tesco Value (it's different from normal tesco insurances and has no bells and whistles at all. It's not quoted on the comparison websites and you need to phone up for it)

Thanks!
If we restrict to over 21s, will be still have plenty of choice of au pair? Worried we might restrict ourselves too much... Looking for a French one BTW.

Hi,
Our insurers asked for age, if licence held for 5 years and if no claims and accidents for 3 years so that seemed to be the criteria for getting the best deal. So if over 21 and answer yes to the other two questions you get a less expensive insurance than if a younger person or more recently acquired licence.
And yes there many many au pairs, on Au Pair World at least, who are over 21