Yes - Bentley GT and Spur 2003 - 2006 uses VDO Dayton CD. Upgrades are easily got from
http://www.navteq.com/index.html
I upgraded my 2005 Bentley Spur CD with a 2008 VDO Dayton CD – works perfectly too.
Make sure it is a VDO Dayton CD compatible with MS 5xxx systems NOT C-IQ devices.
See this official website:
http://www.navteq.com/index.html
This guy sold it to me for 70 euro:
Profundos-Vertrieb
H.Weegen
Vereinsstr.13
31157 Sarstedt
Tel. 05066-90 22 37
Mobil: 0162-6946728
Fax: 01805- 8890 888 43 (14 Cent/Minute aus dem T-Com Netz)