Electrical everything went to hell. I put a CD player in, followed all the directions (which took forever... horrible engineering by Buick), and the following problems arose due to this:
Power locks died
Power windows on one side of the car died
Overhead lamp died
Warning lights died
The gas gauge is horrible. Take a turn and you go from full to 1/4 tank. Depending on where you sit, you can have either nicely over a half tank of gas or a quarter tank left (this is assuming you're the driver and not lounging heavily to the left or right).
You may notice I had a short lived life with this car. When driving home on I95 one night, the car started to sputter. I got off the highway and the car died. A couple minutes later, a guy didn't notice my blinker lights and ran into me. I might have been out of gas, but the meter said I wasn't even to the warning area and no "you're out of gas" light went on. Good thing this is a large car. The guy wasn't doing more than 50 MPH and the impact literally put the whole trunk into the back seat. Luckily I was alone or anyone in the back would have been dead.
The last problem is the overall design of the car. DO NOT try to modify this car whatsoever, this includes simple things like getting an amplifier installed for a stereo system. Unless you drill a new hole through the firewall or take the engine out to put the wires through an existing hole, there's no safe way to run the wires into the car. I have also never had such a hard time finding a battery in my life. This car is truly designed for older people who don't touch the hood of their car and have a mechanic do everything. HORRIBLE engineering.
Engineering blunder. See what has gone wrong.
VERY comfortable drive. This car was honestly more soft than my bed. I considered sleeping in it one night.
Nice V6 for pickup. Would take on my older Accord V6.
A lot of cargo space which is always nice.