Disassembled all four coil connectors and low and behold, 2 pins with failed crimps! The wire was snug but if you lightly tugged while holding the pin it would move slightly. Heat and vibrations would definitely cause the connection to break.
Luckily I had some spares left over to replace them with. Went over all remaining pins and re-crimped for good measure. Went for a long drive after and the issue is resolved.
With racing being canceled this year thanks to the 'C-19 response' I had to get some fun in before the weather turns. Got some new tires and took the MSP on it's longest trip yet.. Drove a little over 1400 kilometres past Wells Gray Park and back. I was hoping to see some epic mountain views but everywhere was smokey from the fires down south which then turned to rain. Weather aside, the highway was so smooth and such a blast to drive, car ran great and handled amazingly.
It was a rewarding feeling to have the car perform so well after all these years and countless hours spent making everything work. Fuel mileage has been exceptional as well averaging about 600km per tank!