depending on what state your in, its most likely required to have a front license plate. it sounds like the previous owner bought a license plate delete strip/molding. this is what i have just bought, b/c im currently driving around illegally without a front plate, it looks better.
but youre right the front piece does pop up with the use of a screw driver, BUT after you pop this piece off there will still be nowhere to mound the plate, therefore you must go on a website like www.bavauto.com
or some other bmw site, and find a front license plate molding, they will have the places for the screws and such drilled in.
if you dont buy a piece like this and just stick your plate on it will look awful
<span style='font-family:Arial'><span style='font-size:14pt;line-height:100%'>T-Mac</span>
95' BMW 325is Jet Black, 5 speed
Xtec 6000k HID kit, DDE Enhanced, Euro Ellipsoids, M3 Front Bumper, Color-matched rear,
Alpine Mp3/CD, 20% tint, M3 Contour Rims, Smoked Corners, front lip
Clear Side markers, K&N Performance Filter, Debaffle, Color-matched side skirts</span>