i just completed one door. i wanted to try out just one, before i continued on.
i went with a 3/8's OD vinyl poly tubing, i did have to use a snake, but no soap.
if i went with the 7/16's OD, it would have called for some slippery stuff.
the door is not too difficult to close, but does require alittle more effort.
off to Lowe's again to buy some more tubing. only 2.81 for 13ft. for each rear door.
the driver's door may take an extra foot.
i will repost after a trip down the road and back on the road noise.