Hi Paul, as I am now officially an 'Old Git', I qualify for extra discounts and I insured my V6, fully comp. with business use for me and SWMBO for only £220. That was with no NCD, as that is used on the other cars and I anticipate only doing less than 4K miles per year plus we live in a very low crime area.
I looked into multi-car insurance as offered by one of the insurance company's on the idiot lantern, but that was MUCH, MUCH dearer.
I did find out subsequently, that as one of our policies is with Saga, we could have used a system they call 'mirroring' whereby they will insure multiple cars and apply the NCD to the lot!

. That was too late for me as I'd already stumped up the money for the insurance with another company and if I cancelled I would have got fleeced.

Saga do not broadcast this system, as I was only told by one of the telephone assistants whilst querying another matter.
So if you are over 50, with at least 3 years NCD, try Saga. I'm not recommending them, but if it means you can get affordable insurance, I'm willing to spread the word.
Handyman