Car insurance sky high!!?

Ok right i am with admiral. and i had a vauxhull vectra 1.8 and i was paying 1800 a year so around 150 a month. now 6 months later i bought a new car HYUNDAI COUPE 2003 and i did a quote and it was 1.480 a year which is like 125 per month. now i rang up admiral and they now charging me 2880 and i need to pay 260 pounds per month! that can be right ! i rang and they said its cos i switch cars.. whats that got to do with it... is this right? cheers