My $0.02...
Yes, white convertible is kind of girly. Although when I came home with my jet black 135, surprised the wife, she asked "why did you buy a girly car". That said, so is the 3series. I once parked next to another 328 same yr and color, when I had mine, and an older woman got out and said " nice car"
just put some mods on and some aftermarket wheels and you'll be fine. Nothing looks better than a white 135 with a black roof and black wheels imo