Northern and salt-belt E36 M3s commonly develop rust at the rocker panel bottoms (often from inside out), jack point cups, rear fender lips, trunk-lid seam near taillight drains, and battery tray; California and Southern cars are increasingly priced at significant premiums, and 'Japanese import' cars typically show only surface oxidation rather than structural rust.
Rust patterns: rocker panels, jack points, trunk seam, and undercarriage
BMW E36 M3 (US-market, 1995-1999) · paint-and-body