For ages I've noticed my roadster leaking from the rear-top of the windows (both drivers and passengers.. windscreen and rear window are fine).
Eventually I came to the decision that I'd have a look and find out possibly why this was happening.
Putting the roof down and removing the roof spar, I then procedeed to pull the seal off (partly, as pic) and push it up by about a few milimetres. As shown below :
You should get a small lip/indent in the seal towards the top, where roof spar will cover. Don't worry about this small lip, as if anything it will just catch more water!
Also, as a small measure you are probably best doing this to catch any other drops that evade the seal itself.
** REMEMBER TO CUT ALONG WITH THE LINE ON THE SEAL IN THE BACK. LOOK CLOSELY, THE CUT HAS A LINE DIRECTLY BEHIND IT**
Put the spar back on, put the roof back up. Might sound crazy but test it yourself with maybe a watering can on the hose on mist setting.
All should be well
P.s, you might be better putting a little silicone on the inside of the under-spar catch. It lies forward slightly, so the water is pushed against the front wall.. which no matter how hard it is pushed against the side-spar - water WILL evade it without the silicone.
Repeat on other side!