Best insurance deals for learner drivers

[Wheels64]

My son will be 17 soon and will be learning to drive. He doesn't need his own car (despite what he says) so will drive mine (a VW Touran - not cool!). I know the insurance is going to cost me an arm and a leg but has anyone got any tips for negotiating this minefield? Thanks :)

We started by talking to our own insurers, and had him added to the policy - it was much cheaper than anything we could find through comparison sites. He might get his own no-claims buidling up while he's still a learner, which can help once he passes his test. That's unfortunately when it gets more expensive, as he'll be out unsupervised then. But a non-cool car will help keep the costs down.

Thanks :)