I really need help!

[Donner]

I drive a 1999 Porsche Boxster (engine is located in the back of the car), it has 68,000 miles on it. And its a manual transmission.

Before this all happened, I saw a red light blinking by the temperature gauge, I asked my dad what that meant and he told me to just ignore it. Also, when I crank up my car, there is a red indicator pointing to my trunk, but after I start driving that indicator disappears.

I drove to work, and everything was fine (I go to work at 7:00 AM and leave around 4:00 PM). Came back to my car, got stuck in a huge line of traffic so I held the clutch halfway down and the brake all the way down and slowly crept up the line (Can't completely stop because the traffic is moving slowly). While at a complete stop for about 6 minutes, I smell a horrid odor. I look over to the right and see white smoke coming from the right ventilation of my car.

I got scared so I left the car there, and got a ride home from someone else. I came back, added water to the water dispenser and drove it home, and everything seemed fine. The red light blinking by the temperature gauge disappeared. But the red indicator with an image of my car pointing to my trunk still remained.

What's wrong with my car? Thanks ahead of time!