The 3 series are great cars I had 2 325i's with no problems, especially BMW's 4 year maintenance warranty... you can't beat that. As for your Boxster, I just got an 97, where everyone on the forum to stay away from. Knock on wood things seems to be good so far. I got a great deal on it and I'll take care of her hoping she'll do the same for me. If you decide on trading in your car maybe we can swap out the Litronics. I'll pay you some cash and send you mine?
You can't go wrong with BMW, I was at the BMW drive last week and got to drive the new 325i... nice. So much more features and feels really solid. It even has the angel eyes. I ended up selling my 325i and stepped up to a 745i. It's sad to see the Boxster go, but it seems like she's taken cared of you for some time and maybe it's time to pass or on to someone. Good luck.