Looky all the holes on the Berlin Turnpike where caches could go. Not anymore. POP; SNAP! Filling the Gap!
These are all Pop-Top Pill Bottles in the usual places of parking lots (tree, pole, guardrail); most in high muggle zones. 
SQUEEZE sides of pill bottle to POP open the top.
PUSH top into bottom to SNAP it shut. Make sure it SNAPS.
Bring you own pen.