the rack trap is the answer. it's a subtle bra pocket that allows you to stash your essentials: the cash and the plastic.
it comes in 5 different colors. 1 goes for $7.95 or you can buy a 4-pack for $19.95. brilliant. check it out over at theracktrap.com.
this reminds me of my late nana who used to stash her cash in her bra back in the day. years ago, i was no older than 10, my nana misplaced her money. we - aunts, uncles, cousins - tore her house up looking for this missing money ... probably, on the low, thinking such and such probably swiped it. low and behold, after an hour of searching, her money pops up. where was it? in her bra. ha!