First Advice: Choose a car that has naturally cheap insurance!

The car you drive is the largest factor in your insurance price. As another website puts it:
One of the ways to control the cost is to make sure the car the teen will be driving is not a sports car. Although many teens want to drive a fast, sporty car, the cost of insuring them can be prohibitive. Keep in mind that the higher the horsepower rating is, the more the insurance premium will be. Choose a vehicle that does not have a high theft rate to help keep premiums low.
Older, heavier cars are not as easy to drive recklessly and therefore are safer and less expensive to insure. For an older car that is paid in full, the consumer has the option of dropping collision and comprehensive insurance and carrying only liability insurance. This will also reduce the rate. And with older cars, the blue book value is lower which also reduces the cost of insurance.
Couldn't have put it better myself!

With this in mind, here is a list of the cheapest cars to insure (average) from broker Adrian Flux (in no way affiliated with this blog):

Car model/engine size Male Female
(1) Classic VW Beetle £932.00 £714.00
(2)Vauxhall Corsa 1000cc£1320.00 £1052.00
(3) Peugeot 106 1000cc £1320.00 £1055.00
(4) Fiat Panda 1000cc £1323.00 £1058.00
(5) Austin Mini 1000cc £1325.00 £1058.00
(6) Fiat Uno 1000cc £1330.00 £1058.00
(7) Citroen Ax 1000cc £1334.00 £1060.00
(8) Peugeot 205 950cc £1334.00 £1060.00
(9) Renault 5 1000cc £1336.00 £1060.00
(10)Vauxhall Agila 1000cc£1336.00 £1060.00


Hope this has been helpful!
Tim