Anybody know what to do? I just clay bar'd my car and a couple weeks later stuff is already on paint again?

I throughly washed and used meguiar's clay bar on my car.looked flawless for about a couple of weeks and i'm seeing stuff back on the paint. Was I suppose to do something else? How can I prevent objects to stick to my paint?I really don't want to clay the entire car again.Considering it literally took 6 hours to do it right.Any professional advice? -Thank youAnybody know what to do? I just clay bar'd my car and a couple weeks later stuff is already on paint again?
do it again. 6 hrs??? i've clay bar'd 2 vehichles in that time but either way it sucks. after you clay it wax it very good