To prevent water, position tonneau cover close to back window?

To keep water from being sucked under the cover due to turbulence, do you place it as close to the back window as possible or as far away while still covering the bed? Mine is close to the window and when opening the tailgate, I get a drip into the box.

 

Not sure what you mean. I've the stock toyota trifold cover that I order with the truck. It's been pouring all day, and its perfectly dry inside the bed. When the truck was new it use to get a few wind blown drops inside the driver side walls of the bed, but as I've use it more, everything has settled sealing out any moisture.

 

If it is a roll-up cover center the front rail of the cover over the front rail of the bed. It should not be too close to the window as the bed does flex and under stress you don't want it contacting the window

 

Thanks, I am checking the turbulence with a streamer. Looks like just centering the front will work, like Gatafly said. I though the cab might cause turbulence and in a rainstorm it could do strange things.