Burning Oil
 

Today I took my car out, let it warm up to 180°, then drove it hard for about 15 minutes, and when I got done, I smelled burning oil, and my oil had gone down 1 notch on the indicator. I see no leaks, no white smoke. It's 40° out, and it hadn't been driven in 4 days.

You do realize that 1 notch is just a few ounces
Did you check the oil under the same conditions?
Same temp? The car was in the same spot and level?

All same condition, level surface. But the oil was still consumed

I had a similar smell...might check your spark plug tubes to see if it's leaking from there onto the exhaust. You cannot be sure it's consuming oil if you're only using the fickle digital readout. Pull your dipstick and check it there.

As said, check cold, re-check cold - same conditions
If you have a dip stick - use that, it's your only accurate way. The gauge will always read lower after you drive

If it's not the tubes leaking, what should I suspect?

Follow the trail of oil. If you're unsure, clean it up with some simple green and check again. If you don't have a leak, and you have so evidence it's coming through the exhaust then I'd guess you're mistaking that smell for the boxster smell. The boxster is mid rear, the engine gets very hot and you're likely to have a small buying oil/rubber smell after a long drive.

First things first, check and see if it's spark plug tubes, oil fill tube or even valve cover. If you find the oil, it's easy to find where it's coming from.

My coolant light has also come on, looks like either a very good coincidence, or I'm about to be in for some very expensive repairs

Oh Man!!! Good Luck.

That's weird. started it back up today after letting it sit for hours and no coolant light. Checked coolant before a cold start and it was normal looking, a little bit lower, but normal. No oil contamination in the coolant, no visible coolant contamination in the oil. The car had been sitting for around a week when I started it this morning and had the light blinking. Should I be worried?