I know, and I found it strange when this friend of mine was saying it's 'well known' but there's little out in the public domain about it. He was racing in the Porsche GT championship last year and his team mate runs / ran a dealership and explained it all. Despite it, he picked up an 04 Cabriolet (don't worry, we gave him stick!!) and sure enough the very thing happened. Apparently the drive shaft vibrates (not entirely sure what causes that bit) and it has a knock on effect through the engine. His actually spat bits down the exhaust. As long as your 2 year warranty is in place, it makes no difference.....
Anyway, this detracts from the fact you've replaced a gorgeous Zed with the car you want. In my book, that's great, and really hope you enjoy it.