I've just today fitted a W8 to my '05
Ibiza FR Tdi and I didn't find it easy at all. Next to the light in the roof in my car is the interior sensor unit for the alarm and it certainly got in the way!
I ended up shaving of loads off the rear left hand side of the W8 and a bit of the casing for the sensor too.
Not having done one before I found the wiring an absolute doddle compared to fitting the bloomin thing in the roof liner. Still I've now made it into the 'I've Got a W8 Light in My Car' Club
On a point of note though, my having a centre sun visor does hold the lining and W8 better. BTW, I'm not keen on the fact the W8 is only held in by two clips at the front and rests on a near flimsy piece of plastic at the back. I'd certainly have preferred screws for sure
I'm typing this after going for a drive at night to see what I thought of the W8 - my partner thought it stylish...I'm not convinced yet but think I'll grow to like it. The W8's W5W bulbs feel like 100w at night
I certainly doff my cap to anyone who comes up smiling after fitting one of these to a high standard in a short period of time... it took me hours to do!