I bought my 135i about a month ago, and got my JB4 just a few days later. I had to take my car in for service, so I removed it, then it snowed, and I had to reschedule for a few days later. I HATED driving the car without the JB4!! It's easily the best $500 I have ever spent on a car. You get SO much more power, it's very customizable, and like everybody else said only takes around 45-an hour to install. I can remove or install it in about 25 minutes now though
