Finally got my Eis Sport installed over the weekend, and so far i love it.
A few thoughts.
1. It's definitely louder on cold start - not too loud, just enough to let you know it's a V8.
2. It's got a great tone especially in the lower rpm range, sounds great cruising around town.
3. Drone is virtually non-existent.
A happy camper so far.

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E90 M3 // Jerez Black // 6MT
Dinan, MS stage 1, V1 hardwired, LUX angel eyes