An idea were can I find a face plate of cq-rx450u of Panasonic car stereo so I can buy it..

fixya site doesn't do spares of any sort

Hi. Locate the connector on the rear side of the plate and clean it with soft towel (and a drop of acohol), so the contacts are shiny. Try the same on the unit. There is also usually an reset pinhole on the face of the unit when the face plate is not on it. Try to locate an press with something thin.

try pacparts.com.

if im not mistaken, that model has a detachable face plate. What happens a lot of the time is the connections between the face plate and the unit get corroded. Take the face plate off and (with fine grit sand paper) lightly scuff the electrical connection clean on both the unit and the face plate. It also doesn't hurt to use a little dielectric grease before you reattach it... this method has work several times in the past for me... Hope this helped!

My friend have in car panasonic Cq-vx 100u them forgot the code. now Ineed a defaul code please sir.

Sorry, there's no way to repair the CD, if faulty. Try looking for a "reset" a VERY tiny hole somewhere behind the "door", on the face of the radio chassis...Using a paper clip end push into the tiny hole for a few seconds, ignition/radio on...If you can't find a reset...take it to a friendly local car stereo shop and ask them to diagnose the problem ($40).
Good Luck

this may be a pre amp only deck
and if it is ou have to buy amplifiers to make the speakers work

same plug size as any ordinary stereo phone plug (ipod)

The 12 volts lights that illuminate the face plate are burnt inside and should be replace. It's a common failure on any face plate.

you have to purchase an adapter to fit an aftermarket stereo into a car. you can buy one at wal mart and the come with instructions just buy the one for your car. make and model.