With so little space for even the most essential components (like a sump), is there any scope at all for air con to be fitted to the car?
Minis sold in Japan from around 1994 had an air conditioning system fitted to them. God knows how they fitted it all in under the bonnet, and the interior parts of the system don't look they were a lot of good for passenger leg-room, but it worked... so it can be done.
Also, having gone to all that trouble of fitting central locking to a boot that's now chock full of lumps of Toyota and a fuel tank and might just be able to squeeze enough room for a few cans of beer, will you be echoing the earlier work of Wood & Pickett and E.R.A. and fitting a rear wiper to fill what little space is left?
Where to conceal a battery and spare wheel are important questions. Air con may be considered only if all engine-related components can be sited satisfactorily.
The Air con unit needn't be fitted to the engine. Something like the electrically powered compressors from a Nissan Leaf, Renault Zoe, or even a Tesla are physically very small and can be fitted in a remote location. There are even aftermarket compressors designed for such applications.
