Probably the most popular 5 Series among BMW enthusiasts is the E39-generation. Most of that popularity comes from the E39 M5 being the best M5 in the
BMW 5 Series (E39) model guide - Prestige & Performance Car
BMW 5 Series (E39) model guide - Prestige & Performance Car
What to Look for When Buying a BMW E39 M5? - autoevolution
The BMW E39 – Five things you need to know
The BMW E39 5 Series is the perfect modern classic
BMW M5 E39 (1998-2003): PH Pocket Buying Guide - PistonHeads UK
BMW M5 E39 (1998-2003): PH Pocket Buying Guide - PistonHeads UK
Buyer's Guide: BMW E39 5-Series Touring (1997-03)
BMW 5 Series (E39) buyer's guide - Classics World