My car also leaked quite badly in the rain though I do not have a sunroof.
In my case the front door seals had actually shrunk and would no longer fit the perimeter of the frame. In both top corners the seal pulled away from the door frame, this allow water to run down the B pillar and onto the rear floor, this being the lowest point.
My solution was to get a piece of matching door seal from the scrap yard and splice in a section on the bottom. As a point of reference, I needed to add 2" on the driver'* side and 3" on the passenger side. Once the seal was completely glued back in place I sealed the top edges with a flexible thermoplastic sealant to ensure water didn't get behind the seal.
40th Anniversary Edition
13.074 @ 106.579
FWI | 4" Intake | LQ4 | N* TB | Custom TB Adaptor | Ported SC | 2.8" Pulley | Custom Intercooler | Ported LIM | Custom Ported Heads | 105# CC Springs | Modded Retainers | Oil Restricted Push Rods | CC OE-R Lifters | XP Hot Cam | TOG | HF Cat | 2800 ST | 3.29 Gears | DHP PowrTuner | LC-1 Wideband | Engine now retired |