My lovely S2K: I usually wash her every 7-10 days. During the non-winter months, I'll wax her every 4 weeks or so. During the winter months, all bets are off. I will give her ONR rinses as needed, temperature permitting. This winter she will be protected by two coats of Blackfire Wet Diamond. If I find a need a little extra gloss, I wouldn't be surprised if I were to apply a quick coat of Ultimate Quik Wax after a wash.
My wife's CR-V: I usually wash it every 2 weeks and will apply a coat of Ultima Paint Guard Plus every two months during the non-winter months. I could stretch out the intervals, but UPGP is just so easy to apply, it seems wrong not to re-apply it every other month. During the winter months, I will ONR the car or take it down to the local coin-op, as needed. This winter the CR-V will be protected by three coats of Finish Kare 1000p.