Use 303 protectant on everything in addition, you can use it on the leather too, but I would probably get something like Tim mentioned to clean and condition them first. The 303 will clean it though...but I prefer it as a protectant because it's so expensive.
I was hesitant to try 303 because the damn stuff is like 20 bucks a bottle at West Marine, but it's AMAZING. You only need to use a little, and it lasts about 6 months. You can just keep wiping the dash, etc. with a clean cloth to get the dust off. It actually repels dust too.
It makes everything look new, without that n00bish Armor All too-shiny appearance. It restores plastic windows for Jeep tops, removes chalkiness from boats and RVs and stuff, you can spray it on your instrument cluster if it's clouded and it brings that back with minimal streaking. It specifically blocks UV rays like sunscreen does as well. I have no idea what the hell is in it, but it was developed for aerospace use. Great stuff!
Here's the encyclopedia for everything you need to know:
A good place to buy stuff:
You really need to get into the site though, they use all kinds of acronyms for products and it can drive you nuts until you learn them all. I still haven't.
For wheels and tires I wouldn't use any of that shortcut stuff that does both. It might be okay, I'm not an authority, I just don't trust it. You can google it or see what the reviews are on that site I posted though...maybe it's fine. What wheels do you have? If you wind up with wheels sans-hubcaps, I'd use Poorboys wheel sealant on them, it's this wax you rub on. Then stuff doesn't want to stick. Since I'm cheap I use the Armor All (I know) tire shine on my tires, but I wipe all the excess off them before it dries. The one with the gold cap, not the black and yellow can, that stuff sucks. I don't like using it, but I'm trying to save money. It doesn't have petroleum distillates in it, so it shouldn't crack the tires, but I think it has silicone, and that's not exactly good for them either.
Autopia would say what you (and I) should use...one of my friends uses some "super secret tire shine sh*t" and he won't say what it is! I think it's a gel though.