Thanks for watching my videos. The front and rear windows on series IIIs are known to leak. They actually glued the windows in but the aging rubber dries and shrinks so that is where the water gets in. Very common and a big job to replace. I personally use clear flowable silicone and carefully lift up and squirt the silicone under the rubber. You want to be sure to get the flowable type and mask off all the paint so you don’t make a mess. If you haven't already be sure to check out the Jaguar Forums for more information on this. Note that series 1 and 2 cars used a different sealing method so be sure your looking at series III relevant material (1979 to 1987). www.jaguarforums.com/forum/xj6-xj12-series-i-ii-iii-16/