Originally Posted by trans-african
and where are border formalities done? The nearest town?
This is old info, but it looks like it's the only you can get:
1) You do all the exit-formalities in Nguigmi.
2) You leave Nguigmi from the airport, the biggest track
3) Somewhere around the border you will probably meet the army, they will check if you have a valid visa
4) At Rig-rig (or another village, not sure) you will meet "immigration", back in 2001 this was a very unfriendly place. They showed pictures of tortured kids and wanted huge bribes. I met some French people who had left more then 1000€ here, they had to interrupt their Transafrica-trip and sell the vehicle in Djamena to get some cash.
Anyway they stamp your visa and off you go.
5) At Bol you will find customs, they will stamp your carnet (and ask for money)
6) You have to register at the immigration in Ndjamena within 3 (?) days after your passport is stamped in Rig-rig. I did this a few days to late but it worked out.
It's not allowed to take pictures without a permit, you might ed up in jail and it's not pleasant.
For me Chad was a bad place; problems with police, problems with the army, problems with my security-situation, problems with the Sudanese embassy etc. In fact most people I have met who have visited Chad had some problems.