Hi guys, I looked into this last year, when Toby and Jago were racing.. Jago has his 6x6 expedition truck on the continent and we were looking at selling seats onboard to chase the Dakar.. excellent trip and a good price, but it kept cropping up about access to bivouacs and actually seeing the racing..everything was on a wing and a prayer in this respect..if you were lucky, then you could blag it, otherwise, you would be looking through the fences!
I was very surprised by how reasonable the costs of the official ASO hospitality tours were....which guarantee bivouac access amongst other things.
Perhaps a good option for a real trip of a lifetime chasing the Dakar, would be to buy/hire a vehicle in the first country, and chase yourself, then at the first border, drop the vehicle and do a couple of the ASO organised trips, this way you would see it from all angles, get tired and dirty chasing it.. get the access to bivouacs, buggies to vantage points in the latter stages and the chance of helicopter trips etc..
Not to mention all the cool swag you would get!
Just my thoughts... but this is the way I would consider chasing, to avoid all the headache of border crossings with local vehicles or buying/selling down there. A few friends have chased on bikes, and one of them is married to Patsy Quick... noone better to schmooze some bivouac passes, and even they found it a struggle! ASO are no fools and with the popularity of the race in SA then its always going to be tough getting access.
Good luck and id love to see how you choose to do it in the end