1994 Roadmaster Wagon - 219K miles - V8 - water on floorboard and road noise

After the first rains in Nor Cal there was a puddle of water on the driver side floor board. Anyone out there have similar problem? Where could this leak be coming from? What did you do to fix it?

Also: periodic vibration from back end of wagon. It comes and goes at 70 mph and 80 mph (yep - got a led foot). Could this be the rear end going out or just need new tires? Maybe a loose bolt?

(Gonna be on the freeway today and will pay attention to the speeds it happens at. First thought it was road noise - but now thinking it is something else.)

After the first rains in Nor Cal there was a puddle of water on the driver side floor board. Anyone out there have similar problem? Where could this leak be coming from? What did you do to fix it?This could be a door seal, windshield seal, or cowl seal, hard to tell from here!Also: periodic vibration from back end of wagon. It comes and goes at 70 mph and 80 mph (yep - got a led foot). Could this be the rear end going out or just need new tires? Maybe a loose bolt?This could be tires, universal joint, trans mount, drive shaft bearing support, axle bearings, or rear end. Once again, nearly impossible to diagnose from here. Take it to a trusted shop (if there is such a thing in CA!)