I'm in a pretty significantly modded 328 E93.
In a wide open parking lot I too am trying to park far away. I would park next to an M3 for sure but leave a car space between us if it was really that wide open.
In a tight parking lot where you can't park far away with any more open surrounding space than any other area, I would still park didectly next to an M3 or similar car. Likely I would put my driver door on the side the M3 is on and it's my way of saying your car is safe on my side. I open my doors carefully. And it's also me saying hey you're car is sweet so I wanted to park next to you lol.
Eibach Pro kit|Bilstein Sport Shocks|M3 Edition Grilles|Painted Reflectors|Matte Black Vinyl Window Trim|CF Performance Spoiler|35% Tint|19" Satin Black Avant Garde M359|Lux H8 V3|OEM Aero Lip|M3 Side Skirts|M3 Mirrors with Performance CF caps|LCI Tails|M-tech Rear|Duke Dynamics CF Performance Diffuser|Cyba 4.0 Black Chrome