duke i know its a bank, just couldn't remember how to spell it ( which makes me wonder about the value of their advertising
) as you pointed out despite what we like to think the cars are very similar, if you want proof just look at the skins available for the bf1, even though the car is 2 years old, you can still tell what team some one's picked because the colours are more important than the shape. spec wings would be a great start to reducing costs and would have the advatage of allowing them to be designed to work with each other to allow cars to follow in each others slip stream.
the problem with spec parts is that teams compete in f1 for the " constuctors" championship, not a team championship and as such they will probably baulk at any attempts to lessen their design input into the cars.
however it has to be said that for most of the seventies, apart from ligier and ferrari, the teams all effectivly used sped engines and gearboxes, i.e. the cosworth aand hewland units, so i would imagine a standardised transmission would be an option, you could allow the teams to design their own case for it but use standard internals. also at the same time, re introduce a manual "H" shift as there it's far cheaper to manufacture, the engien manufactures may complain that the drivers wouldn't be able to modulate the throttle accuratly enough to avoid damaging the engine but if you introduced the transmission change with new engine regs they could ensure the engines are suitable and i'm sure that if they knew they had to get their curent engine to work with it, they would soon find a way.
one of the problems currently is that the engine manufacturers have gone from being suppliers of major components that teams could choose between to being the most important group with controlling interests in teams. when they first began investing heavily it was pointed out by a few respected jounalists that it might not be ideal for f1 to find itself in a position where it was "scared" to introduce changes that were unpopular with the manufacturers currently involved incase they decided to either leave or start their own rival series, something which they have since threatened till they won concessions. the balancing act comes in recognising this but also the risk that eventually f1 may go the way of the dtm, ie. become so expensive that only a couple of manufacturers remain as others find that investing £ x 00 million a year to be beaten by rivals is not good for car sales, at what point does the average car buyer start to noticed and be affected by the fact that the car in front is one of 6 in front of a toyota ? that honda engine expertese is slower than toyota's and renault's ? and that mercedes powered cars are obviously better driving machines than BMWs ultimate driving machines? BMW has an understandable history of pulling out when they are consistently not winning and feel that they can achieve better results elsewhere, so do mercedes and toyota, renault and honda have both walked away from f1 in the past whilst being at the top.
BMW recently announce a 44 % fall in pretax profits for april to june 2008, in 2007 pretax profits fell by 6% despite an increase in sales of 9%, to a figure of 3.1 billion euros. if the 2008 quater figure is reflected over a year that will become 1.7 billion euros or approx 2.3 billion dollars. a f1 budget of 366 million dollars reflects about a 15 % increase in profits if it is cut out.toyota's profits are about 4 times as large but have fallen 28% in the same quarter. honda onthe other hand after failing to meet profit targets in recent times finds its profits are up, an achievement it feels is due to its small economic car range and also a favourable exchange rate with the us market which comprises half its non motor cycle sales. renault's profits have also risen but having anounced 5000 redundencies and possibly more to follow may face increased preasure in france about expenditure. mercedes have had their profits fall but still expect to make 11 billion dollars and ferrari's have risen to 59 million euro's in the first quarter this year. if these trends continue then you may find that companies such as bmw have to reconsider their position, that honda may still be affected due to their reliance on the us market and that renault may come under increasing domestic preasure. ferrari need to be in f1, it's their original reason for existing and it would be almost unthinkable for them to pull out, mercedes and toyota have such large profits that they probably can ignore any savings a reduction in commitment would bring them. torro rosso are already looking for a buyer for the end of the 2009 season due to rule changes and they will rquie a major investment to coomence making their own cars again.
obviously team budgets are to a large extent paid for by sponsors but it should be remembered that in the economic down turn of the early 1990s fi team numbers fell from 18 in 1991 to 10 in 1996.
finally if you want to encourage fuel consumption either ban refueling during the race or reduce the refueling rig flow rate so what is now an 8 second stop became a 16 second stop and then after so many years reduce the flow again to make it a 24 second stop.