I was wondering if any body out there that has installed Certainteed cedar impressions  has any tricks  to lock in a panel after the fact , i mean i always look under to make sure the panel is latched before i nail it  but the other guys don`t they just hustle along, and i noticed they had a couple spots where the panel was`nt locked in yet the whole wall was already sided.Now i tried taking two flat head screwdrivers and pushing up on the tab from underneath the course to see if i could get it to latch and also tried a vinly zip tool but neither worked .That siding is so ridgid that there does`nt seem to be any room for error at all. Mean while i have spoken to them about looking before they nail the panel on.