Here is the complete list of unlockable achievements in Forza 4 for the Xbox 360.
There are no secret achievements to unlock in this game.
Amateur (25) – Complete the first year of Season Play
Autocrosser (10) – Complete 10 Autocross events without hitting gate cones
Awesome Drift (20) – Earn a perfect Drift score
Born Competitor (30) – Post a time in every Rivals mode event
Bucket List (80) – Finish 1st in every single race in the Event List in Career play mode
Car Explorer (10) – Fully explore any car in Autovista
Champion (25) – Complete the ninth year of Season Play
Clubbed Up (15) – Create or join a Car Club
Clubman (25) – Complete the second year of Season Play
Daily Rewards (5) – Visit the Message Center on at least five unique days
Driver Level 1 (20) – Reach Driver Level 1 in Career mode
Driver Level 10 (20) – Reach Driver Level 10 in Career mode
Driver Level 20 (20) – Reach Driver Level 20 in Career mode
Driver Level 30 (20) – Reach Driver Level 30 in Career mode
Driver Level 40 (20) – Reach Driver Level 40 in Career mode
Driver Level 50 (20) – Reach Driver Level 50 in Career mode
Elite (25) – Complete the eighth year of Season Play
Entrepreneur (10) – Sell a car tuning, paint job, or vinyl group from your storefront
Exclusive Taste (50) – Own the five most expensive cars in the game (not including DLC)
Expert (25) – Complete the fifth year of Season Play
Factory Driver (60) – Get any Car Manufacturer to Affinity level 50
Ferrari Collector (40) – Own every Ferrari included on Disc 1
Flat Out (5) – Earn a perfect Speed score
Forza Faithful (15) – Import a file from Forza Motorsport 3
Forza World Tourer (60) – Finish a race on every race track in Forza Motorsport 4
Grease Monkey (10) – Create a car tuning file for your car
Here’s My Card (10) – Create a custom playercard with badges and titles
Kingpin (5) – Knock down a gold bowling pin in Car Bowling
Legend (50) – Complete the tenth year of Season Play
Legendary Battle (15) – Beat a Ferrari 330 P4 in any race while driving a Ford GT40 Mark II
Look Ma, No Controller! (5) – Use Kinect to drive any car in Free Play
Masters (25) – Complete the seventh year of Season Play
My Car is Your Car (10) – Share a car in your garage with your Car Club
Nice Pass (15) – Earn a perfect Pass score
On Location (20) – Take a photo of any car in every Home Space
Outta Time (10) – Reach 88 mph in a DeLorean
Painter (10) – Create a paint job or vinyl group for your car
Perfect Turn (15) – Earn a perfect Turn score
Professional (25) – Complete the sixth year of Season Play
Rivals Shootout (10) – Race and defeat an opponent in Rivals mode
Semi-Pro (25) – Complete the fourth year of Season Play
Show Off (10) – Upload a movie to Forzamotorsportnet
Slipstreamin’ (5) – Earn a perfect Draft score
Speed Demon (10) – Reach 240 mph in any car
Sportsman (25) – Complete the third year of Season Play
Star in a Reasonably Priced Car (10) – Complete a lap around the TopGear Test Track while driving a KIA cee’d
Unicorn Hunter (10) – Be the winning bidder on any “unicorn” car in the Auction House
Welcome to Forza Motorsport (15) – Complete the very first race in the game