How would you react?

Meredith left home before me this morning, and called me to inform me that the skinny vanilla latte she purchased from Starbucks made her feel like she was "on crack". As a disclaimer, I can say with complete confidence that Meredith has never used crack, and I don't believe Starbucks brews it in their coffee. So I decided I was going to Starbucks as well. I placed my order in the drive-thru and grabbed my coffee just like any other morning. But when I looked down at the cup in the cupholder, I noticed that a little coffee was leaking out where the seam of the cup met the lid. If you know what I'm talking about, I hope this doesn't bother you as bad as it bothers me. The reason it bothers me is because it never fails that coffee will drip out from under the lid onto your crisp, nicely ironed dress shirt and camp out there the rest of the day. And we all know that nothing impresses a prospective client more than a huge coffee stain on your shirt! In my effort to correct the barista's error, I grabbed the cup from the cupholder in an attempt to adjust where the seam met the lid (so it wouldn't drip all over me). OF COURSE, when I picked up the cup, the lid came off, revealing that said barista had filled the cup ALL THE WAY TO THE *%#@ LIP OF THE CUP!!! Which sent scalding hot coffee sloshing all over my hand and console. While en route to work on a curvy two-lane road. This did not make me happy. You can imagine the thoughts that raced through my head. My first instinct was to turn around my car and speed by the drive-thru window, hurling the scalding hot coffee cup through the drive-thru window at a velocity that would make Nolan Ryan jealous. Then I realized that, without an explanation, a scalding hot, hurled coffee cup would not correct the mistake, and inflicting damage without explanation is terrorism, right? So I took a deep breath, or ten, and tried to call Meredith to get her to talk me down before my brain boiled. But got no answer. I was still fuming, but did realize that the cup hurling would not be Christ-like, so I backed off of that idea. I have now had time to think about it, and I think that my best course of action would be to call the manager, and suggest in a constructive way that they might want to consider putting LESS COFFEE in the cup before handing it to an unsuspecting driver. Also, a temperature of 211 degrees Fahrenheit is neither appropriate nor enjoyable. SO...my question is...How would you react?