Here is the full list of all 16 Colin McRae Rally achievements. It takes around 12-15 hours to unlock all of the achievements on Windows.
Complete the Australia Rally Series in 1st place
Complete the Mixed Rally Series A in 1st place
Complete the Mixed Rally Series C in 1st place
Complete the Expert Rally Series in 1st place
Compete in at least 1 rally in Australia, Greece and Corsica
Finish a stage with all four areas damaged to the maximum possible amount
Start a stage in the Mitsubishi Lancer
Complete a rally in 1st place for the first time
Start a stage in the Subaru Impreza
Start a stage in the Lancia Stratos
Complete the Introduction Championship in any finishing postion
Complete the Greece Rally Series in any finishing position
Complete the Corsica Rally Series in any finishing position
Complete Mixed Rally Series B in any finishing position
Complete your first stage
Start a stage in the Ford Focus