I think too many people have an inflated sense of their car's worth. We're talking about a 3 series here, not some handmade italian exotic. 3 series, including m3, are a dime a dozen on the autotrader. It won't become a collectible just because it has a N/A engine, a high redline, high specific output, yadda yadda. 13 years ago honda made the s2000 with a N/A engine that revved to 9000 rpm, and made more hp and tq per litre than the m3 engine. should we also collect ap1 s2000 and shrinkwrap them so that we can sell them for a couple million bucks each 50 years from now?
Cars are an awful "investment" of money. Put your money into bonds or real estate instead.