Is the BMW E46 M3 a good investment?

The thesis

The last naturally aspirated inline-six M3 and a modern classic with legendary S54 engine. Manual coupes in excellent condition with low mileage (sub-50k miles) now trade £45–65k; high-mileage examples sit £25–35k. Low-mileage examples in desirable colours (Interlagos Blue, Phoenix Yellow) are firmly appreciating. US production ~50k units; scarcity of pristine manuals plus 'last of breed' status underpin value. Mid-cycle—already recognized—but sub-30k-mile garage-queen examples with Competition Package continue to climb and align with the low-mileage brief.