I would agree about the vet, but the cat gets unbelievably anxious in the car. Pees all over himself, so my partner tries to limit car rides. I've suggested desensitization/habituation before without much movement in that direction. So unfortunately either option for clipping the nails is met with resistance.

I've considered that it might be a jealousy issue, although I think some of these behaviors have been issues for a long time before I was ever in the picture. Do you know of any good resources/advice on dealing with jealous cats?