Welcome and I hope you enjoy the Forum!
From my perspective, I have also enjoyed Roundel (BMW Monthly Club Magazine), my local BMW CCA Club and Track Day Events.
As for mods, this Forum is filled with information and suggestions. The answer on what is best for you depends on how you plan to use your M3.
Have Fun, enjoy and again Welcome!
ESS VT-1 550 | M24 Oil Cooler | Fall Line Half Cage | RaceTech 4009W | 6 pt Harness | Lifeline Zero 360 Fire Suppression | Rear Seat Delete | Motion Control DA Dampers w/remote reservoirs | 900/650 Hyperco Springs | RD Sport Sway Bars | Brembo 380 BBK | GC Camber Plates | Michelin Cups | Eisenmann Sport | Stack Gauges | Painted Challenge Front Lip | Painted ZCP Rear Spoiler | Xpel Ultimate Film | LuxAngelEyes