Wondering if there is a long-term solution to the bad design of fuel tank mounting / location.
1. The 2- and 3-speed M3Ws (if I recall) have a fuel (or combined fuel+oil!) tank in the front scuttle / under the "bonnet". I suspect a bit of reordering of the oil tank / use of a compact LiPo 12v battery might leave room for a decent tank, passenger side, say courtesy of https://www.conceptracing.co.uk/fuel-tanks-swirl-pots/ ?
2. Probably a good space would be in the passenger footwell, subject to a suitably "safe" construction and bulkhead?