Speakers and old amps cd players

[chuck88]

I have several questions:

I have heard that speakers wear out is this true?

I have two old Kenwood amps, they work fine but they are 20 years old. Would it be wise to replace them or a waste of money?

My 88 GT has a rough ride and I was thinking about buying an in dash cd player and I was wondering about in dash cd players skipping when the car goes over bumps. Do they skip often? would it be unbearable to listen to cds.

Thanks

Chuck88