Check your break and clutch fluids as we had problems with ours at about noon, probably because of the heat. When crossing the Mauritanian border if not declaring all the dosh do not keep it in your wallet or next to the drivers seat. You can also take some pens to give away. Locals seem to have liked it. You do not need a guide for the Atlantic route. Get sahara overland coordinates and description and as long as you are in 4X4, there is no problem whatsoever. Off course, the grids were taken in 1996 so the piste does not follow the coordinates in straight lines but it is still easily done. We had no previous experience in the desert and even overtook some of the guided convoys. Also do not forget that you can not really use VISA card in Mauritania apart from the capital. I think there is only one place in Nuakchott were you can get a cash advance. Also whatever happens try to avoid flying from Nuakchott, it is a right pain just getting on the plane.