540i rear lights

im sure many people have asked quesitons about the rear lights of a 2001+ 5 series. But my question is are the actual lenses the only thing diffirent? According to a service tech at BMW, to upgrade all you need to do is buy the lenses, they say the light output is the same module as on the previous 5's. They also claimed that the 5 does not have LED's in the rear, they said it's just what the lenses have in them to appear the way they do. Is this service guy correct? Has anybody 1st hand knowledge of this? Thanx.