BMW 1M or M3, CTS-V, GTO, Mercedes AMG, Jaguar XFR?
Perhaps a new Malibu SS (when they come out)
If you expand the limit to include AWD cars, then you can look at Mitsubishi EVO's, Subaru's, Audi's
They all blow the weight limit you require out of the water, but with the right technology they can get decent mileage (freeway), but they can be had in 4-door (even wagon form for some).
How about a Lotus Evora? RWD with room for 4 (well two adults and two kids) and probably the lightest 4-seater outside of the FRS/BRZ with the power you're looking for.
350Z is a two seater. BMW parts cost scares me a little, and the Mustang is cool but just too porky for my taste. Of all the ideas I've heard so far, my first thought (boosted FR-S) seems the most logical and most affordable.
How old are you willing to go???
E7 Corolla offers 7 full roofed body styles all with rwd.
As far as the power... you will have to add/build that.
mines got about 170hp and gets a tick over 31mpg @ 70 mph
OR... if you want to stay inside the Nissan family... a 510 can be a fun little car with an SR20, corrected rear suspension, and adding rear disc brakes
Jcamper
New Reader
2/26/13 2:03 p.m.
SVO with a holset and more boost? Little heavy though. Mine is right at 3000 pounds. I drive mine about 100 miles/day, haul kids (7 and 9) every day too. Respectable autocrosser (not me, the car). J