I got my 2008 LT Malibu in May 2013. I have to say that it is comfortable to drive and the gas mileage is great. I get about 26-28 driving in the city and 30-35 highway. I mostly have been hitting 31 mpg. This car has had no problems and runs great at 99k miles. I do however plan to trade in this car for a chevy cruze this coming spring.
Bought my 2008 LTZ 2.4L used in February 2011 with 28k on the clock. Soon after, the electric door locks failed - would not stay locked. Replaced under warranty. March 2012 the drain tubing from the sunroof came loose and ended up filling the passenger footwell with water. Self-diagnosed and repaired with a bit of silicone putty and super glue. New tires at 77k. Routine oil changes and brake fixes - but one time in North Carolina the front calipers wouldn't fully release. $200 to re-build the calipers. At 85k, replaced timing chain and intake/exhaust solenoid valves @ $1500. Around 88k, the service air bag light came on. The dealer has told me the seat-heater melted the passenger sensor module and both need to be replaced @ $1100. Currently unresolved.
Now the good stuff: This is the best car I've ever had. I've found myself wanting more power at times, especially when climbing mountains across the country, but the 2.4 is sufficient. Great mileage, also. I've been getting about 25 mpg combined with mixed city/highway driving. Seats are totally comfortable - 7,200-mile cross-country road trip @29 mpg with zero complaints. The front doors do open a little bit far, but they have three stages where they stop. #2 is a good opening point. It's still a little bit difficult to tell exactly where the back of the car is when backing in somewhere, but I've gotten used to it. Not looking forward to the labor-intensive process when a headlight goes out, but I changed foglamps myself without issue. I would buy it again (but I would get the V6).
I have 111K on my 3.6L LTZ. I still like the quality interior and have been in few mid priced cars that can match the interior quality. It still runs and handles like new barring a minor squeek hear and there.
The only thing that has gone wrong is that I had to replace one power door lock mechanism. It's slowly loosing oil and coolant after 111K miles, but I think I can get at least another couple years out of it before I'd have to fix it. Also, the chevy key fobs are junk, and break but are pretty cheap to replace. I
Have had the car for 3 years bought it with about 10k miles. Now has 49k miles on it, just got tires and they tell me the ball joints are bad and surprised the tire hasnt fallen off yet. The car has made a popping noise, the steering wheel isnt straight and the locks on the back doors do not work...well sometimes the driver side back lock will open but not lock back. Over all the amount of money for the car for the value isnt great, i have had other cheaper cars that havent had any problems like this.
Overall I enjoyed my car when I first bought it in 2008. I have had to take my car in four times in the last three months. Things that have gone wrong in the last 2 years: replace door locks (driver side front and back), keyless remotes, exhaust and cam solenoids, emergency brake, tires, brakes, OnStar system, Intermediate shaft in steering column, and numerous sensors. I am happy that I bought the extended warranty. I recently have had to put new brakes on the car and new tires. The car only has 55,500 miles on it. Will never own another GM product.