My wife and I did a self drive of Namibia and Botswana in May of 2018, after I hunted in Namibia. We loved it! We had a company map out a route for us, and had planned accommodation every night - ranging from tents to lodges and a couple nicer hotels thrown into the mix too. We only drove during the day, and I brought a GPS along (used coordinates instead of address), and kept a cooler stocked in the back seat. Took a Toyota RAV-4, and had no problems, although if I were to do it again, would probably beef up the vehicle to a smaller truck or 4x4 of some kind. All in all, we did over 5000kms (3000 miles) and saw Namibia on our own terms, in our own time. Road conditions ranged from gravel with pot holes to smooth as silk tarmac, and everything in between. Just drive according to road conditions, and you will be fine. The lady who plotted the route for us made notes on the map telling us what conditions to expect, and how long it would take between destinations. All fuel stops and places to buy cold beer and ice were marked as well.
Now, Botswana on the other hand, pot hole city. We had to really take it easy once we left the Caprivi strip and headed down south to the Okavango delta. We got scammed by the Botswana Police as well, lots of "Radar Zones" (looked like a hairdryer to me), but we rolled with the punches, and took it as part of the adventure. T.I.A. - This Is Africa.
If you possess any sort of adventurous spirit, I highly recommend it!