Anyone ever turn an old Dart into an ultimate daily-driver?

That's what I did with my '72 Challenger. Still my daily driver for just a bit longer until I get my Duster on the road. But after I went through the suspension and brakes and did a few bolt on mods to the engine (4 barrel, headers, electronic distributor) I've driven it over 40k miles in the last 5 years. I drive it year round, although that's a bit easier in California than the rest of the country.

As far as mpg's, you need some tuning in a BIG way. I get 16-17 on the highway with my 318 and 3.23 gears, and that's in a heavier Challenger. I usually get 13-14 around town, but I drive it like a musclecar so I could probably do better. I got 17-18mpg with the 2.76 gears it came with. :D

Don't let anyone tell you that you can't daily drive one of these cars. After I initially went through everything and rebuilt the suspension and tuned the engine etc I've done very little work on the Challenger, mostly just normal maintenance. I did initially spend a few thousand dollars getting it to where I wanted it, but I also did more than was necessary - Hotchkis UCA's, 1.12" torsion bars, 11.75" disks and 11" drums, 17x9" rims with 275/40/17's, streetmaster intake with a 625 Carter, Hooker Super Comp headers, B body 8 3/4 rear with 1" offset hangers, and a few other goodies here and there. Since then its been a very trouble free car, and although I'm going to be pulling it off the road to finally fix up some body issues the mechanicals are still doing well.