Kids car seat for 2004 Hyundai Tucson

[banksysbird]

I can't be the only person who has this car and kids and cant get a dam car seat to fit in the back? It has Isofix but they (mothercare) can't seem to get any car seats to fix into them as it seems the points are really low down and the fabric has been stitched too tight so the opening isn't wide enough? I was going to get a stanley and fix it but thought id see who recommends what on here first. Dont fancy cutting my seats if I can help it!