Estimated trophy difficulty: 2/10 (Platinum Difficulty Rating)
Offline: 30 (12 , 13 , 4 , 1 )
Online: 3 (2 , 1 )
Approximate amount of time to Platinum: 20 hours
Minimum number of playthroughs needed: 1 x Career, 1 x Multiplayer, Multiple Single Races
Number of missable trophies: 1 "Hotshot"
Glitched trophies: None
Does difficulty affect trophies?: No, all trophies can be earned using easy mode.
Do cheat codes disable trophies?: No cheats
Online pass required?: No
Step One - Career Mode
The first step to your Platinum trophy is to play and complete career mode to 100%, ultimately unlocking "Vision becomes Truth" for your efforts. Along the way you'll acquire a handful of story related trophies and you should aim to polish off some of the miscellaneous task based trophies also, although a fair amount of these may come naturally as you play. There are three trophies I highly advise you work towards right from the outset namely "Riot", "Test Driver" and "Hotshot", the latter of which being the only missable trophy in the game. I wouldn't go as far to say these trophies are a pain, however, it could be argued they require you to go against how you'd ordinarily play to earn them, so it’s best to start going for them early on.
Through career mode you also need to complete and win 4 championships in both areas of the game world, those being the city and autobahn areas. Once available the championships are accessed via the precinct spawn points in each location, and completing this step will net you all the game's vehicles, along with the "Garage Owner" trophy.
Step Two - Single Races
With Step One complete, the next task is to unlock the trophies associated with single race mode. You need to complete a race on every track to unlock "Track Tester" and should earn the "Pro" trophy along the way, as the tally of wins you gain here will be in addition to those you accumulated during career mode. The "Race King" and "Off-road King" trophies are tied to the Spirit-Raceway R and 4x4 Club Circuit R tracks respectively, so be sure to incorporate going for these two trophies as you progress through all the tracks. Finally, the last trophy you'll earn via single race mode is "State of Emergency" which is unlocked for causing 1 million dollars worth of damage during one race. Please refer to the Trophy Guide for the ideal settings to unlock this trophy.
Step Three - Multiplayer
The last step towards the Platinum is attaining the three multiplayer trophies - "First Online Victory", "Unlimited Health" and "Godmode". Unfortunately the online servers are a desolate wasteland, and there's no doubt you'll need to find yourself a boosting partner to complete this step. Please refer to the following thread to find a boosting partner:
Trophy Boosting Thread
Personally I found boosting these trophies a real chore, not because the actual process is tricky or time consuming but as a result of countless connection losses midway through the boost. Whether this was an isolated issue for me or an issue that is common for multiple parties, I cannot be certain. Should you face the same situation just try to be patient, persistence will eventually prevail. Please refer to the Trophy Guide for the ideal settings to boost these trophies.
[PS3T Would Like to Thank Puzzler for this Roadmap]