Not a lot, if you want to drive everywhere.

Namibia is a stunningly beautiful country, but it also huge. If you want to do more than just scratch the surface, I would recommend a stay of not under two weeks. Preferably three, if you have the time and money.

I do not think the dry season is the best time to visit Namibia, unless you want to spend your time at Etosha's many waterholes. In that case October and November are good months. Otherwise Namibia is at its prettiest in March and April, especially after a good rainy season.

Johan