There is another thread about where a carnet is needed.
To my mind, a carnet is needed in ANY country that is signed up to the agreement: see here for a list: Public - Carnet de Passages en Douane
The only debate is whether the personnel on duty when you hit a border are clued up enough to understand what they should or should not be doing.
The exit process/stamping should not be done if the entry was not completed.
Percentage wise, I think Egypt is the highest. Cant remember if its 500 or 800%. Either way, the carnet I got last year, included all countries and specifically Egypt. This was issued in France and cost no more and no less and the bond was the same, no matter what countries it was used in.
My friends on the other hand was issued in the UK by the RAC and specifically excluded Egypt.
All depends on who's on the gate...
Nostradamus Ate My Hamster