Do yourself a favor and locate a 6spd manual car to test drive. Try to get a nice prolonged drive so you can take it out on various road conditions. Don't be afraid after the test drive to look at the car from different perspectives, set the seats as you want, sit in the back, climb in and out of front and back, bring something you normally or occasionally carry w/you and see if it fits in the trunk, bring your iPod and 1-2 of your favorite CDs and play with the radio etc...
I know from your previous posts you want to make absolutely, positively sure you'll want that 135i - imho there's no better way to make sure besides test driving a physical one.
I've been on 5 so far