Originally Posted by babymog

When really cold, the 602 doesn't burn enough fuel to stay really warm, especially with the heater blasting and/or a not completely closed thermostat. Check the temp gauge. If the engine is running cold, it is possible that it will not burn the fuel completely and have a little white smoke. That will go away after the first launch, heats up the cylinders.

Nope, once up to temperature, the engine is running between 81 and 87 degrees. Has a new thermostat in there.

The clattering? Run some good oil, try something like Mobil Delvac 1 to clean it up, might be gummed-up lifters (hydraulic) from poor oil maintenance. Likely unrelated to the smoke.

According to previous owner, the engine has had Rotella T 5w40 synth for the last 2 years (but was driven only about 5K in those two years)

Another possibility of the smoke (there are many possibilities) is the turbo leaking a little oil into the exhaust, when you accelerate the hot exhaust will burn the oil residue out of the pipes, then it is hot enough to combust without smoke until it idles again.

A couple of thoughts, good luck. Wunnerful engine and car.