does anyone know if the m5 exhaust will fit the other 5 series cars in the e39 group, if not what aresome good exhasuts made that will fit the 5 series.(similar looking to the original m5 exhaust) thanks

No. The E39 M5 is a 5 liter V8 and the exhaust is designed for this engine only. The largest non M E39 5 series is a 4.3 liter (540i). You have a few good tuners that you can look into.

Dynan, I believe makes high performance exhausts for the 5 series (including the M5)
Hartge
AC Schnitzer
Turner Motorsport
Hamann
Remus

These are the most popular tuners. I'm sure you will be able to find more through a search on Google.

I hope this helps.