The road between Turkmenbashi and Garabogaz is really old and in bad condition.
From garabogaz till the Border of Kazachstan (45 km) there is no real road. Just a sandy and stony pist . (Don't drive here while rain).
We recommend you to plan 2 days from Turkmenbashi to the Kazachstan Border.
The 50 km after the border in Kazachstan is although not really exist Verry bad