Just buy a smaller engine. I absolutely hate stop/start. You could change your oil every minute and it still doesn't get around the fact that you're starting up from zero oil pressure every time. It hammers batteries and it hammers the starter motors. You're garunteed to flatten your battery with a relatively low rated alternator like you've got. Also, it's something you can almost get away with when you have direct injection but with indirect you're more likely to just borewash the cylinders with multiple start-ups without any milage in between.
Just fill it with petrol and drive it normally. If that gets too expensive, get a lower value, smaller engined car.
Its not that I can't afford to run my car, it's only a zetec ... I don't know if it's just something amongst some nerdy people I know, but there's just a certain coolness about their more modern German and Japanese cars that look good, do 60 in around 6/7 seconds and still rarely see the pumps because they do around 45mpg combined... whilst 45mpg is still a figure I would associate with 1.2l hatchbacks.
I guess technology is just pushing on, and that the Cougar has been around for much longer than it seems, and what its looks still suggest.
A smaller engine would just ruin the experience. I think the nicest solution would be to swap the engine for an advanced turbo engine out a later ford.. but that would be quite unrealistic judging how much work would need to be done to make it fit etc.
Ford just need to develop a gorgeous Cougar 3 with the 2l focus st engines in them, and hope they have a similar marketing flop for them to become good used buys