Replace that unused ashtray with something you need.
 
CNC machined from textured ABS plastic and fitted with custom sized cups.
 
For use with 82-92 Camaro
 
Installation:
You will need to either trim your existing shift plate or use a custom shift plate. Using the cup holder plate as a template, clearance the underside of the center counsel to allow the cup holders to fit. The plate will be shipped with the cup holder inserts loose so you can use the plate as a guide for trimming the center counsel. Once the center counsel is cleared you and glue the cup holders in using your choice of glue (2-part clear epoxy is what I used) and install.