$10k sports sedan...

I'm looking at picking up a sedan with manual transmission for street duty, but would still be fun to take to an occasional track/autocross day.

Ideally, I'd like to buy something for $6-8k and spend $2-3k in upgrades/fixes because I know these vehicles are going to be older and probably need a little love.

Wants:
- 4 doors or at least comfortable for 2 adults and 2 kids (I think we'll drive it more if 4 door)
- manual transmission (non-negotiable) 
- fun, good handling chassis
- want to keep the car fairly stock'ish (wheels, tires, shocks, maybe light springs, brake pads)
- 20+ mpg a plus
- non-premium fuel would be nice, but not required
- quick enough on track to not be a road block like my old NA Miata in the instructor group at VIR...

Here's my running list...

BMW E46 330i
BMW E90 325-330i
Subaru WRX
Acura TSX
VW GTI
Audi A4
Civic Si
S197 Mustang GT (coupe, I know)
8th Gen Civic Si

WHAT ELSE?! Any advice is appreciated.

SI, either generation. Drive it more, fix it less. 

In reply to Floating Doc (Forum Supporter) :

Great motto. I would add in G35/G37. 

Mustang or a Civic

I know you said sedan, but I've noticed the price of Fiesta STs has really been dropping. For your budget I suspect you could get one that doesn't need anything, other than better pads and maybe better tires. It would likely be newer than the other options you've listed.

I really like mine, it's really fun, has a good sensation of speed, practical and economical. It only gives up a few hp when running 87 octane. Parts are readily available from other models (engine is is same as the escape) or regular fiestas. 

2nd Gen Mazda 3 or Mazda Speed 3

It's been a while since I was in an S197, but from memory I wouldn't call them full time four seaters. 

I wouldn't expect the rear seats in a S197 to be used for anything other than children of single digit ages.

I'll also help your list by suggesting no German cars. And that's from a guy who used to be exclusively European cars.  Just not worth the endless headaches.

Another vote for Mazdas. They are so overlooked.

RWD: E90

AWD: E90

FWD: Civic si

I'll vote E90.  My 328xi 6spd (AWD inoperable) has a comfy back seat, gets 30mpg highway/26 suburban, has 292k on the original unopened motor and transmission, still sees occasional track duty.

If you go e90 get a 330i. 

In reply to dpspeed :

Your final words were: 
WHAT ELSE?! Any advice is appreciated.

I see that Mustang is on your list but Camaro is not.  The Mustang never offered a 4 door but the Camaro kinda did...

Cadillac ATS is a small sedan (and coupe) that is a chassis-mate to the final generation of Camaro.  Rear drive, 2.0L turbo that could be had with a 6 speed manual.  www.fueleconomy.gov say it was rated for 19/23/29 but does say it only calls for 87 octane!  
Think of it as Cadillac builds a BMW 3-series competitor.  If you're a long legged driver the rear seat may still be cramped for adults...maybe.  

A sample in Georgia:  '14 w/83k asking $11k