I made a dumb mistake in swapping front lens caps between 14mm and 20mm when I sold 20mm. Both 46mm size, but 14mm one is slimmer. Sound silly but the few millimeters difference does make noticeable difference since the pancake is so tiny.
The price of the slim cap is $25 from ebay. No one else sells it. Geez. Adorama sells original Lumix lens caps for 46/52/62/67mm at cheaper price, but that's not the slim 46mm cap. Some suggested Leica slim lens cap at $27. Nah.
Luckily the buyer agreed to exchange the caps. Thank gawd.
Thanks for the advice stonebat ! Didn't thought there was a difference, although I noticed dramatic variation in size for rear caps :) (noname ones/olympus ones/genuine lumix ones).
They certainly will start to offer camera in plain recyclable package soon, you'll need to pay extra to get CD, any cables, charger and battery will be optional, and strap will be sold separately.