I've been doing some serious freezeframe viewing of Cars and taking notes. I noticed that the locations page here for Radiator Springs was incomplete and contained innaccuracies. Decided to map the town and these are my results.

Looking down the street towards Route 66 from the Traffic court/Fire Department/Sherrif's office building at the top of the main street, the businesses on the left are:

1. Foggy Windshields

2. Mr. Curb Feeler

3. Sparky's Spark Plugs

4. Unnamed store with 'NEW PARTS' sign in the windows

5. Rusty Bumpers

6. Eat (All day lunch painted on brickwork below sign)

7. Wimpy's Wipers

[Narrow alleyway]

8. Luigi's Casa Della Tires

[Road headed out towards Freeway 40 or Cadillac range]

9. Radiator Springs Curios

10. Cozy Cone Motel

11. Tow Mater Towing and Salvage

12. Radiator Springs Municipal Impound. 

The businesses on the right are:

1. Mrs. Muffler 

2. Muddy's Mudflaps

3. Carburetor repairs Emporium

4. Miss Piston

5. Pop 'n' Patch

6. Lubeorama

[Alleyway. Blocked at back end by a fence]

7. The Oil Pan

8. Ramone's House Of Body Art

9. Ramone and Flo's home (behind Ramone's House Of Body Art)

[Road leading to Willy's Butte]

10. Flo's V8 Cafe

11. Ornament valley mechanical Clinic

12. Sarge's Surplus Hut

13. Filmore's Organic Fuel {Including Filmore's 'Taste-In'}

14. Budville Trading post (small building hidden under the overhang of the trees on Filmore's property)

15. Glenrio Motel

16. Unnamed small building 

17. Radiator Springs Garage

18. Radiator Springs Drive-In Theater

There is a narrow road behind this side of main street stretching from the Drive-in theater to the road out of town to the Wheel Well Motel. Which is why Flo has a 'Drive-Thru' sign at the back of her cafe. The other side of main street has no back road. 

It's worth noting that in Cars 2 Flo's V8 cafe got an extension built onto the main building on the side nearest Ornament Valley Mechanical Clinic. The small unnamed building between Glenrio Motel and Radiator Springs Garage was demolished and I think I'm right here, but the Garage itself was missing from Cars 2 but reappeared in The radiator Springs 500 1/2 short.