Andre, coming down , enter the Eastern pan, about 10km west from Nata and drive South towards Kubu. Don't do the Western pan from Gweta ! Stay close to the edge of the pan ( about 100-200 metrs is fine ), This is for safety reasons if there is wet patches and also if theres an off or a breakdown so you will be visible to other people.
Heres some fotos of a trip I did in 2007 with Zoeler (now in OZ

). We entered from the South and drove up to Nata.
Ad the end of the pan (coming South) you will eventually hit the vetenary fence. Turn right/west and continue to the Tswagong gate where you enter the last couple of kilometres to Kubu. Whatch out for holes in the road next to the vet fence made by anteaters etc. Its about a 70-80 km trip. Take enough water and don't leave your buddy/ies behind ! Enjoy !