Is there any merit to what they claim with the Detroit Tuned kit? It's more than $100 more than the OEM kit, but if it were more resistant to stretching/failing, there's no dollar amount that isn't worth making the death rattle go away.

 

We use all OES parts in our kit due to the warranty MINI has of 2yrs on their parts. We made our kit with the sprockets that we use in our shop and have installed many of them with no issue.
Check it out as it is very cost effective.
http://www.waymotorworks.com/timing-...-cooper-s.html

 

I'm not sure what's in that kit, but there is some good info about the 11317607551 82mm tensioner update (superseded by part # 11314609482), which is the final 5th Gen redesigned tensioner and is much smoother. Some good info here and here in these NAM threads. Let me know if you have any questions.