I've had both the interior and exterior replaced on my (then) '04 645.
The interior was due to a fraying of the top due to a problem with the strings that pull the top into place. The top was replaced due to the sensor issue that is common with the very early model year cars.
The problem started while under warranty and continued nearly a year past the original 4 year mark. I have a very good relationship with my SA (nearly 10 years) and he went to bat for me with BMW. I had to pay $500 (skin in the game I suppose), but they replaced the top.
Nick / TopDownInFL (sans the "top down")
2012 650 Coupe - Alpine White / Black Interior / M Package / Premium Sound
2008 650i Convertible
2004 645Ci Convertible - Reverse Sensors / Reverse Camera
2005 545i Sedan
2003 330Ci Convertible
2001 330Ci Coupe
1998 323i Convertible
1995 318i Sedan