hi guys im trying to figure out where the water is coming from , during heavy rain i have lot of water accumulation on the floor driver side , i mean about 1 to 2 inches of water , does anyone ever had this problem ,,,thanks

Two questions: do you have climate control? Does this rain enter when the car is parked or moving? If the answer to the first is yes, and the second is moving, then there may be more to this than a drain, as I am finding out in my 96 855 w/ climate control. Water will enter the passenger compartment when moving in rain, but only in defrost mode. This, I believe, is a blend door issue.

Hope this helps.

I agree with 850stylzz, it is probably coming from your windshield.

I'd take the wipers off and remove the plastic cowling, check its drains and take a good look underneath it.

Good time to add a pollen filter if you do not have one.

Actually, before you try that, you could just run a hose back and forth across the windshield and watch where the water goes.
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96 855R, 95 855,854, 90 744 Ti - 340,000 Volvo miles put on 7 bricks

The front drain tubes may be clogged. Lift the hood and check the
area around the wipers to find the drains. (I think you can also see
them running down the firewall, engine side.)

Similar to the two drains found under the trunk lid (at the window), two additional drains are found just below the wiper arms above the firewall. Make sure they are clear of debri including all other drains mentioned.

Ok, lets think about this logically. You state that you have 1-2 inches of water buildup after a heavy rain. Seldom ever does an area get 1-2 inches of rainfall in a single drenching. Therefore, it is logical to conclude that your collection source is substantially larger than your receiving source. I think that may rule out the sunroof. I do however think this makes the front windshield a good candidate. I think this is one of the few places on the car that would have the ability to collect and distribute that amount of water to your interior. Check your windshield gasket and surrounding areas (just below and to the side). Id bet dollars to doughnuts that is where your leak is coming from.

If you have a sunroof make sure the drains are open.