I'd say get a new-er 135i ...F you want a new car. I would not buy the iDrive option. I did not order it on my car... and I don't feel I am missing anything.
The only options I would order that I did not is rear PDC and HK sound system. I only ordered; Leather, USB/iPod, heated seats, and full M-sport and metallic paint.
And YES, I would buy another 135i.