Easy "Kinda naked" Achievement
Start a new profile, you do not need to do the tutorial, just go to the computer and buy enough car parts to spend the 4000$ (Crankshaft is 250$ a pop, so just buy 16 of them and you should get the achievement)
Get the Most Out of Your Crates
Everytime you open a crate and get disappointed because you got no tuning parts or even two barn maps? Now read this:
Step 1: Save your game by clicking the right mouse button -> save game or Esc->save and go to main menu and load your save again.
Step 2: Open the crate and see what you got.
Step 3: If you doesn't get any good parts then press the right mouse button -> settings -> load game (which loads the last savepoint of Step 1).
Step 4: After loading you repeat step 1 - step 3.
Step 5: When you got good parts then press the right mouse button -> Settings -> save game and open your next crate.
I recommend to open just one crate even if you have multiple ones in your inventory. The reason for this is simply that you would waste crates and have a high risk to got perfect parts in crate #1 but in crate #2 you got 2 barn maps and a normal part. And believe me, i got multiple times 2 barn maps out of crates.
Depending on your system power and the number of mods that you're using this shouldn't take more then 1 minute. Also look for tuning parts with higher +quality because every +quality step gives the part 10% more power increase. For example a +4 quality turbo charger. A normal charger out of the tuning shop will have +10% of power increase, the +4 Turbo charger comes with +14%.
Unlock at What Level
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.
Cheat Codes...