Right, what sizes are the speakers in a '98 420. Mainly the rear ones , and the bass ones in the front doors. Can the front door ones be upgraded independently of the tweeters. I have a big amp from a previous car and can't decide whether to use it or not. Thanks.

17cm / 6.5" in the front, not all cars were fitted with tweeters, and if you don't to use 'em just un plug them.

Not sure about the rears, probally wouldn't be hard to fit a set of 6*9's there though.

I was looking at keeping the tweeters and up grading the bass,in the front. In the back Iwas just going to replace the original speakers, not wanting to go cutting up the car. Thanks anyway.