Hi D.,
I guess this is sort of local! I never thought I would see someone who I actually know on here. I'm C. from Germantown, but I guess you can see that.
Anyway, Erik and I go round and round with this almost every day. Like the other ladies have said, it helps to race him, have him choose his own clothes (even though is choices make my skin crawl sometimes. We went through three weeks of wearing PJs everywhere), and giving him a lot of warning. Also, he has an Elmo doll he loves and we dress the Elmo then dress him.
Other times, nothing helps but a swat on the butt. I hate it and can feel my stress levels getting out of control and have to struggle so it doesn't escalate.
Good luck. this too shall pass, right? In fact, I am writing this reply to you right now as a break from trying to get his clothes on. I hope we aren't late to our first dance class of the term.