new 328iS owner

I just bought a 96 328iS and I have really enjoyed owning it so far. I bought the car from a private owner so it has been taken care of but it still needs several things before it passes my standards.

I replaced the water pump, fan blade, fan clutch and belt last week. I have read that they were a problem area. I have a check engine light on, so I am betting that it's one of the 02 sensors. Since the car is OBDII that means it has two of them right, one pre and one post?

Also the radio display is very dim, i can read it just fine at night but during the day it is tough to read. I order the radio removal tool from bavauto.com. I have a nice pioneer head unit but I like having a changer in the trunk. Are the factory radio's bulbs servicable? I don't mind having to solder a few bulbs here at there. I was just curious if anyone had any success with this.

Any other problem areas for the car I am missing besides the water pumps? The rear shock mounts feel okay to me, I will do them this summer. What in the world is a "guibo" (sp?)?

Any comments, suggestions, stories would be greatly appreciated.

Here's info on the radio display . .
http://www.boston-bmwcca.org/bimmer/2002/10/radio.asp

The guilbo is for a manaul tranny: In-between the transmission output shaft and the driveshaft, there is a flexible coupler that joins the two together. This rubber, reinforced coupler isolates vibration from the rest of the drivetrain, while transferring power from the engine and transmission to the rear differential and wheels.

DIY - http://www.pelicanparts.com/bmw/techarticles/E36-Guibo/E36-Guibo.htm