Ok , I took some pictures and will post them , but first a warning .
The door seal is not the only possible area for an air leak; wind noise; at the entry door . The door glass in my coach came loose from it's mounting glue (?)and I had to remove the glass and reseal it to the frame . First picture.
A member with a coach of our vintage had the door glass blow out onto the road at highway speed, he hadn't realized the glass had come loose.
Also , if like my 99 , your coach has the manual entry door awning , airflow through the gap between the body and awning arms will produce a wind rush sound that no amount of door adjustment will eliminate. Second picture.
I love my Newmar ,
but it's as aerodynamic as a shoe box and I know that at speed , because of all the awning arms on the side and antennas and airhorns on the roof ; it'll never be a quiet at speed as my mini van.
That being said , onto door striker adjustment .
Tools required , pencil and a 5/8" box end wrench .
Before you start , be aware the door latch has two positions ( safety catch picture #3 and fully latched , picture 4) so close the door slowly to see if it latches in the safety latch position with the door about 1/8 to 1/4" away from the body. If the door won't latch there and has to be slammed hard to get it to hold , the striker is already to far in and has to be moved out , if the door does hold 1/8" open the striker gets moved in .
Mark the starting position of the striker with the pencil . Picture 5
Loosen and move the striker slightly 1/16" at a time , until you get the desired tightness of closing without getting so tight that releasing the latch with the handle gets difficult.
Mark the current position of the striker on the door frame , in case you need to start over .