If you are looking for a used Avalon, this is the year to start from. The revised 6 speed transmission is a marked improvement in smoothness, gas mileage, and reliability over the 5 speed autos from 2005-07. There are numerous websites and complaints about thse tranys). Also, the car was freshened on the exterior and has an Ipod plug. The one issue with the '08 model year is the headlamp assemblies, which are a well-documented problem. The good news is that Toyota extended the warranty for the headlamp assemblies for 5 years and 75000 miles from the original in service date. But you have to call Toyota because many dealers will rip off the unsaavy. The Avalon is otherwise a great car.
My consistent gas mileage is 33 mpg highway (usually cruising at 75 mph) and 26 around town, as long as you don't race from stop light to stop light. This is not a sports car by any means, and begs to be driven easily and serenely. Your rewards is a fantastic and comfortable ride, with a very potent engine and yet unbelievable gas mileage. How many 270 HP cars with plenty of room for 5 get 33 mpg highway? My Avalon actually gets slightly better gas mileage than my friend's 2011 Altima, although it has nearly 100 more horsepower! This car has no squeaks or rattles of any kind, and I have to trek up a long, steep, unpaved driveway every day. Also, the materials quality inside is excellent.
The trunk is relatively small for such a large car. The front console cupholder slants so that the drink actually is held at an angle, which is a strange engineering oversight. The long handled telescoping adjustment for the steering wheel feels flimsy and does not fit with the rest of the car's interior quality. It would be nice to have some control over the trip computer, although I like the fact that gas mileage resets every time you fill the tank so you get legitimate tracking various types of driving. If you do drive the Avalon hard, thinking of yourself as a NYC cab driver, your gas mileage drops precipitously. Otherwise, this is the best investments you can make for a family sedan!