Funny none of you found the tools yet or the space under the false bottom in the trunk? sure you did yes
I ask since no one above mentioned it so far ...
So adding to the list of the OP ....
Tools are (including your special wheel lock socket) in the RH tray once you open the trunk (some tools are missing). BTW good place to store your manual is above the tool tray ... then you all knew this yes
Should you hear rattles from the trunk chances are your tools make the noise. I wrap mine in paper towels.
Under the false trunk bottom you find your BMW Mobility Kit (tire inflation kit). Its a good idea to take it out and familiarize yourself with the operation so that you can help yourself if the need ever arises.
Things you may not find in your M3 unless you take them along are;
Flashlight, Tire Pressure Gauge, Reflective Warning Triangle, First Ait Kit and a Blanket.
(I still have to get a litre of oil and at least one fuse of each type for long trips)
A sudden flat or low pressure warning miles away from nowhere my get you to the next town if you can add some air yourself. The blanket might keep you warm while you wait for Roadside Assistance, or to cover some one that just had an accident and is in shock shaking. The Triangle might save you from being rear ended if you have no power at all and are in the dark. The first aid kit may come in handy (one never knows does one).
Since I like to keep my car clean I also carry a car wash kit on long trips. I got one from a customer as a parting gift it is well equipped.
Anyway, those are a few things you will not find in your M3 unless you take them along on long road trips
I thought I mention them anyway.
Cheers now and happy trails to one and all