As Hc4361 indicates, adding a more experienced driver onto your own policy can often see a substantial reduction in your premium. (Boxtops suggestion, of doing it the other way round, could lead to you and/or a parent being sentenced to up to 10 years imprisonment for 'fronting'. It's strictly illegal!).
Additionally, try all of the options for insurance coverage. i.e. check out 'third party only', 'third party, fire & theft' and 'fully comp'. Surprisingly, 'third party, fire & theft' is often cheaper than 'third party only' and it's not uncommon for 'fully comp' to be even cheaper still.
A standard Ford Ka is in Insurance Group 10, with some models being in Group 11 (and the Sportka in Group 15 or 16), so you're at the cheaper end of the range of premiums. However switching to something like a Fiat Panda or Skoda Fabia would take your insurance down to Group 2.
Some insurers also offer substantial discounts for Pass Plus:
http://www.direct.gov...iedDrivers/DG_4022426
Chris