^Excellent. These things cause an undue amount of annoyance.
Just want to make sure folks know there are two types of firewall/strut brace fasteners, and one can be re-torqued and the other cannot.
If you see threads with a nut on top you have the kind that can be re-torqued; if there's a bolt with washer that screws through it should not be re-torqued. The second type is a single use bolt that has been angle torqued. The "reusable" kind is typically the one that becomes loose anyway. This is why I suspect they changed the fastener type of later build Z4Ms.
See
this post. Instruction for each fastener type can be found earlier in the thread, and there's a link over to Ron Stygar's SIBs and other information as well.