CHEVROLET RADIO STAYS ON

I Installed A Aftermarket Stereo And Would Like For The Stereo To Stay On When The Ignition Is Off Until I Open The Door. If You Could Help...

When I Shut The Car After Pushing The Start Button When I Open The Car Door The Radio Would Shut Off, But All Of A Sudden When I Do That...

My Vehicle Listed Above Started Having Strange Electrical Issues A Few Weeks Ago. I Had A Spill Into The Large Tray In The Center Console...