As far as current gas prices go, adjusted for inflation (2010 figures) gas prices are about double what they were in 1969.
EX: in 1969 gas was .35 cents/gallon. Adjusted for inflation, that's ~$2.06 in today's $$.
Seeing how muscle cars of 40 years ago got ~1/2 the mpg of today's muscle cars (probably ALL cars) that means we're spending the same $$ to fuel our cars now as we did then.
EX: I remember my 69 390 Mach 1 got ~8mpg city. My new 5.0 gets around ~16 mpg city.
So at double the price for fuel (adjusted for inflation), it's a wash.
Just FYI ...