Put something on right after you get out of the water
SurfFur Water Parka not inexpensive but very practical in colder climates. If you have a group for a volume order they have given group discounts in the past.
If you aren't changing into dry clothes, this parka or poncho will keep your car seat from getting wet
Warm drink - soup, cocoa, etc. in a thermos will help warm you up
Getting Out Of Your Paddling Gear - if you are going to change before going home
Bring a change of dry clothes in the car
Foam Pad to Stand on - warmer, more comfortable to stand on, protect the gear you are getting out of - keep your wetsuits clean, minimize wear from contact with rough surfaces
No Changing Room? you can use a towel or some that warm robe or poncho you already put on for privacy.
Some robes like Surffur are built to assist changing clothes - roomy enough for clothes changes and providing holes in outer pockets to allow inside access.