So a pretty big update =)
After doing a cruise through Mt. Nebo, I had lost about 800mL of oil. There were no leaks so the oil simply burnt up in combustion. This is usually caused by old piston rings or valve stem seals.
A quick compression test showed all cylinders produced identical compression readings, this rules out piston rings as the cause. When valve stem seals leak, blue smoke is usually seen when you start the car up first thing in the morning. Oil slowly leaks past the seals into the cylinders overnight, then burns up as you start the car up. My MX-5 did something different though... Under engine braking/over-run, the crank case vacuum sucks oil past the seals. Then as soon as you step on the throttle again, huge amounts of blue smoke escapes from your exhaust.
Was thinking about blowing up my engine and putting a new one in, but did my research and found that it's fairly cheap to fix.
So here it goes =)