The convertible was known as the 206 CC, its one good car but not so much for the day to day Kenyan drive. The main problem with this cars is parts and maintenance...especially after Marshalls started having its own issues, no service parts for a 407 which i purchased from them. If you do decide to bring this car i would recommend the petrol as there are very few people in Kenya who will understand how the Diesel works.
If your friend is a returning citizen, he is entitled to bring one car duty free as long as it is in his name and he has owned it for 1 year. In this case i would recommend getting a better car that is more suited to kenya.
Before you can be be old and wise, you must first be young and stupid.