Level 1 - Your Basic Garage. 1-lifter, tire changer, wheel balancer and spring puller, radio and phone.

Level 1 - Parking. One level. You can buy more.

Level 1 - Test Track. Use to determine broken steering, gearbox and suspension parts (N.B. test path does not discover bad steering-related parts.)

Level 1 - Bonus Track - Abandoned Airport. For free roam fooling around. (Doughnuts)

Level 1 - Race Track. For time trials around a loop track.

Level 1 - Car Salon, aka Car Dealer. For buying new and expensive cars.

Level 4+ - Level II Garage Upgrade. Adds test path and repair bench to your garage.

Level 7 - Barns. Go to purchase cars in mid to poor condition. Also random used parts.

Level 12+ - Level III Garage Upgrade. Adds 2nd lifter and parts warehouse.

Level 13 - Junkyard. Go here to purchase mid to poor condition cars and random used parts. Like a very large barn with a great selection.

Level 19 - Auction. Go here to bid on an assortment of cars in good condition (but not perfect)

Level 30+ - Level IV Garage Upgrade. Adds paint shop, cleaning/detailing tools, dyno (later?), a third lifter and a welder (to repair car "body").

Level 35+ - Able to repair car body parts --doors, bumpers, etc. At this point you should be able to restore any car to 100% condition, paint it any color and livery you want, and sell it for maximum profit. Or keep it and admire your growing collection like you're Jay Leno.