w116 450sel 6.9 - loss of power and trying to make it look good

[Mike300ce]

A friend of mine has a 450sel 6.9 and it is going like, well its not really going very quick anymore at all. the engine seems to lack power. and being the 6.9 it should have plenty of power on tap.
it does have a fair few miles on it, but still those engines were built really well so if should still run fine.

anyone know of anything that is a common problem with those motors.

She also really wants to make it look a little different, and she is looking for some inspiration. has anyone got any ideas or photos of what they have done so that i may be able to show her and give her some ideas.

its just an ordinary white 4 door sedan.

if anyone has any ideas on how to make it just a little bit more special or go a little better speak up, please.

thanks
mike