I dont think i EVER only had one car to drive, but when i did daily drive my SS the majority of the time, aug2001-aug2005, i racked up 62,000miles total(im pretty sure thats what it was). So that was like 15.5k miles a year. Since the new motor april2007-november2008 i think i clocked another 7k miles.
As for other random mileage facts....
Now my most recent DD(non-fbody - SKY) i did 11k miles from june 1st - Dec 1st.....
And as for my Denali... like 34k miles since Sept 2005.
My '96 Dodge ram... 67k miles since 1996...
My '85 iroc has 158k miles on original lg4/t5/10bolt drivetrain...
My '89 iroc chassis has 50k miles..
My '79 Vette lt1(just motor)..6,609 original miles

I, myself, have driven about 35 miles total since December 29th, 2008....