The high-revving E92 M3's V8 is good for many things. Putting one under the hood of a 135i, though, might just be the best thing you can do with the old S65 engine. My position on the 1M would be ...

The range-topping 135i does benefit from a few alterations, though. Its lower spoiler juts further forward, the grille is wider to aid engine cooling and vents replace the foglights to channel air ...