Temporary Car Insurance

melb

Evening all! My partner has bought a new car but is wanting to sell the previous one privately. He got 2 weeks extension on his car insurance to cover both cars - at a cost - but still hasn't sold it. He wants to take out temporary insurance for the old car to be able to take people out on a test drive and maybe use for work sometimes but is being quoted ridiculous sums. In the old days you could add a further car to your existing insurance but it seems not now. Can anyone recommend a company that might be willing to give insurance on a week-by-week basis? Thanks for any help.