Hi all I'm new to the forum and only joined because I saw that the post was referencing my Austin Yellow M4.
I was lucky enough to buy one of the last six E92's built in June 2013 and very reluctantly sold it in May 2014 when I ordered the M4.
Shouldn't have been concerned. The M4 runs rings around the E92 in almost all aspects.
The obvious one where it really struggles was the exhaust note. Having owned a C63 with Performance pack I knew what a good exhaust note sounded like.
Yes Bruno at City Performance Centre was v helpful and this was the 1st Akrapovic exhaust for the M4 installed in Australia. He has now done close to a dozen and his back orders are growing. I think Akra are under the pump with in excess of 700 M3/4 exhausts having been ordered - mostly in the US of course.
My son runs "Petrol Fuelled Passion". He takes videos of special cars.
He did a compare of my stock and Akra sounds on
You just need to get your head around any warranty issues. Basically if you have an issue with the exhaust or an issue arises because of the non factory exhaust you are on your own.
I have spent 25k on my fully spec'd M4 and in my mind the "bang for your buck" item was just over 4k for a chip and tune at CPC.
As you know stock is 317KW, 550NM and 0-100 in 4.1 sec.
Try 372KW, 707NM and 0-100 in 3.7 sec!!!!
They thought I should have nailed 3.5 seconds but I'm not much of a driver and I'm happy at 3.7.
You know how I mentioned an exhaust issue would be frowned upon by BMW service if you fitted an Akrapovic exhaust; the chip and tune is easily discoverable when they plug in and you would be up the creek if there was an engine issue.
If you want to see my car my son has a youtube video under Petrol Fuelled Passion entitled BMW M4 Austin Sunrise.
Hope this was helpful