Had my fair share of sunroof leaks, outer seal was replaced a while ago, bought for £58 at the time I think, from Max at frazerpart.com. Fitted myself, easy enough job.
Laterally though, and annoying little leak appeared again, it seemed to be getting past the outer seal, pooling in the gutter, and liping up under the inner seal rear corners, and into the car. The inner seal was old, and quite brittle. I decide recently to purchase edge trim off ebay, 9mm tall, grooved inner grip, and fits to edge of 0.5mm to 1.5mm. Ordered 4meters as the sunroof inner measures 3m 10cm approx.
Removed old inner, cleaned the metal thoroughly, went round the top edge with vaseline all round, then fitted new seal. This has worked well. Cost about £12 delivered. Probably not much different in price to OEM inner, but I liked the look of it better, and pretty sure it offers a tighter fit.
If interested, here's what I bought...
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=200543987261&ssPageName=STRK:MEWAX:VRIIf I get anymore water, then I will be trying this tip.
Cheers