Here is the result of a 5-day binge project (and a year of sporadic updates...), to satisfy my own curiosity as to what can be achieved (by me) in a short timeframe.
This is the answer: A not-quite-finished Honda Racing Lawn mower built by the British based BTCC team "Team Dynamics", based on the HF2620 mower.
Full album of progress from the start: https://imgur.com/a/Zinfl
Modek: SFX (just borrowed from the Dallara, so not a perfect match)
Me: Everything else
Physics wise its a bit of a handful, but its seriously fast having 100+bhp at around 200kg (with driver!). Not the most refined ride by any stretch, but its certainly driveable.
Oh and do not reupload this mod anywhere - just link to here. And do not make any modifications to this without my permission. Thanks