The kit works. It replaces the little rubber guys in the cupholders, and plops in the existing holes. You can see them in
this picture.
The only ashtray available for the post-98 is the one included with the cupholder kit. It could also have been had when the car was new by getting the "Smokers Package". If the car has an actual lighter it had one at one time. Not that its really all that useful as an ashtray.
