You can find a 1999 Chevrolet Corvette radio wiring diagram in a Corvette service manual. The service manual can be found at your local library. Most Chevrolet dealerships will provide the radio wiring diagram free.
When fixing or changing a radio in a car, a wiring diagram will help make sure things are connected correctly. A wiring diagram for the radio of a 1990 Dodge Dakota can be found in its maintenance manual.
240SX came with 2 different lug patterns. All 1989 to 1994 240sx came with a 4 lug 4x114.3 pattern. While the 1995-1998 240sx SE/LE's came with a 5 lug 5x114.3 pattern. Preferrably you'd want to find a wheel with less than +30 offset for 240SX's.