Is the BMW M3 a good investment?

The thesis

The E46 M3 is the last naturally aspirated inline-six M3 and has definitively crossed into 'modern classic' status. Manual coupés in good order now sit £15–23k (median ~£18k), inside budget, with specialist community consensus that the bottom was circa 2017–2019. The S54 engine (343 bhp, 8,000 rpm) and near-perfect chassis balance reward enthusiast driving, and rust/subframe attrition is thinning the herd of clean examples, tightening supply. However, this is mid-cycle not early: values have already appreciated meaningfully from sub-£10k lows, and ultra-low-mileage 'investment' cars are £25k+. Condition and history dominate pricing more than mileage. The car is not a sleeper; it is a known quantity with established collector interest. Upside is calibrated but real if you buy right.