After a minute or so the lovely lady from the insurance company said that there may be scope for up to a further 15% discount as we had two cars insured with them.
She asked if she could put us on hold whilst she went to speak to her manager, we waited for a couple of minutes and then she came back with a renewed quote of £270 and asked "Would we be happy with that?"
Um, yes please

I haven't worked out the percentage discount but I'm pretty sure it's significantly more than 15%