I need a little guidance on the newer model 3 series and 5 series BMWs with automatic trans. She is looking more at the 3 series E46 and E90 models sedans but the 5 series E39 and E60 will be considered. Is one model more reliable with less maintenance issues? She is more into comfort and not interested is high performance, convertiblesand wants higher gas mileage. She wants seats that have more side bolster similar to the sport seats in my 535is.