The 'roo bar' is nice piece of simple yet bold lateral thinking, but it might be safer to just take the 'pay the money' option. That engine mod sounds phenominal but it would spoil the nicely proportioned/easthetically pleasing body profile of the R4. However, if we can improve the fuel economy of the 4 by lightening the load this will enable you to have more money for toll charges. The only unnecessary bit of excess baggage/weight on the 4 is the removeable ashtray - discard this immediately. The 4 is a triumph of minimalist but adequate functional design - more robust than the comparitively fragile 2cv the only other modern contender? With the price of fuel rocketing we need a more frugal 4 - but how?