Removing Stock Head Unit

[412underground]

i just recently picked up a 98 318i. the car has a cassette tape deck and i want to replace it with the cd player i had in my old car. when i went to the local audio store to pick up the antenna and harness needed to put in the new head unit i was told that i have to replace the speakers and stock amp too. i was wondering if this was true? or if i should just install a cd changer instead

[El Presidente]

you dont need to change the speakers.

However, you wont hear much difference in SQ. Amps are also optional upgrades.