Posy has always been difficult about her nails too. She doesn't mind having me cut them, but she won't stand still for it, and her nails retract too easily. I usually only get one nail per attempt, and even then I think I end up cutting the same nail over and over.
So I called the vet on a Saturday morning to see if they could fit me in to get Plum's nails clipped. And when they said yes, I thought about it for awhile and then called them back to see if I could bring Posy as well. Both cats thus were brought to the vet for a quick mani pedi. Posy got a little overwrought, so they said they had to put her in an oxygen chamber. Coughdivacough. I think they just weren't used to the sound her nose makes when breathing--which is something akin to a permanent snuffle and snore.
Luckily, they didn't charge me for Posy's extra oxygen, and I left ten minutes after I had arrived, with 36 short nails and not as much money out of my wallet as I would have thought going in.
Plum in a picture by Sean, showing some of the offending digits: