Great car, cant go wrong in any sense. If you're going to rack on heaps of kilometers on the thing, then the whole collector appeal in terms of coming to re-sell it will not be there. You're going to pretty much have to keep it as a weekend-car-if-weather-permits to retain the super collector appeal.
If you are going to rack on heaps of k's and you're planning to modify it, i don't see any reason to not just go for a M135i, or a 135i Coupe. You can LSD, Front and rear swaybar, coil over, brake / wheels and JB4 it up for less than 10k.
If you're like me, a few cosmetic additions, wheels/tyres (no runflats) and a tune is more than enough for a daily drive