I come to an arduino forum for assistance on an arduino issue, and your best advice is not to use an arduino?
This is an integrated dash (as in F1 steering wheel) I can't wait 30 seconds after every start, stall, every power cycle for the Pi to boot and my gauges to work. In terms of integrated radio telemetry this isn't an issue, as such I use a Pi for this task.
I'm working with the Nano because it is a small, as such easily integrated into the steering wheel, and a well supported micro-controller.
Arduino is also a platform that I'd like to learn as such have picked a project that I believe that it should handle, as in a single threaded simple data collection, some very simple byte manipulation and display.
Back to the issue at hand.
The Nano clearly isn't lacking in clock cycles otherwise I wouldn't get hundreds of main loops completing without a pin 2 CAN Bus interrupt.
Given that it's dropping frames from the buffer without a read I'd guess it's either an issue with the 8mhz CAN Bus adapter (probable), a problem inherent to the arduino SPI bus (doubtful), or an issue with the libraries I'm using.