I was considering getting this and putting in my car eventually...
Well, today I went under my car troubleshooting my driveshaft vibration issue (
http://alltrac.net/phpBB2/viewtopic.php?p=348841#348841 ) and I don't understand how this can fit a stock / stock-ish ST185, since it is much thicker in diamter than the stock driveshaft...
The stock driveshaft already is very close to the exhaust pipes and components (I measured about 2~3mm gap between the shaft and my resonator (HKS 2.5", but very close to stock configuration) and even less, ~2mm gap, between the shaft and the secondary cat on the stock midpipe.
I know a huge percentage of people here have aftermarket exhaust systems (and mostly 3" systems at that), so clearance to the exhaust system may or may not be an issue for you. But I thought I'd bring this up, since this is something to consider.
So for me, if I were to get the CF Driveshaft, I have to change out my entire exhaust system to make room for it.
[I'll post some photos later to illustrate my point.]