i had an old bottle of eagle one nano wax lying around that i slapped on it, after washing with armor-all car wash. i like the nano wax because it goes on and off realitivly easily.
when i get around to cleaning out the interior, i use some lightly soapy water with a cheap microfiber cloth from wal-mart. i stree lightly soapy water, becuase if you use too much it leave a film on everything. sometimes i'll even use just hot water. and a shop vac to clean the carpets and seats.
i don't do much, and if you got too clase to the car you'd be able to tell. one of these days, i'm thinking of doing the dawn detergent wash, and start over on the waxing. (to try to get down to 'fresh' (for a 5 year old car) paint)