Does anybody have a good website for purchasing obedience jumps? I saw some PVC ones on J&J that looked good. Only problem was that they caution against leaving in a hot car because they'll warp (125 degrees.) In Tucson in the summer, it's common to have temps that high inside of a car. I'm wondering if the warp factor is "for real" or should I be looking at wooden jumps. I'd like something portable for training in the parks - that's why PVC really appealed to me.