To unlock this you need to come 1st overall
in every event through all 4 tiers, which can be achievement on any
difficulty. By overall i mean for events with more than one race you can come 1st overall on points.
For me i stuck with the beginner cars for most events as for some reason a slower car gave easier AI, so here is what i used.
Rampage/8 Ball/Knock Out/Hard Target events:Jupiter Del Rio or Lafayette Eulogy
Race off/Domination/Eliminator events:Beliveau Meteor
Head 2 Head/Smash Hunter/Trick Rush eventsFord Fiesta H.F.H.V.
Those are only suggestions to what car to use, use what you are comfortable with.
Use your boost wisely and where possible spin your opponents out.
This will unlock silver and bronze also.
The Silver! achievement in DiRT Showdown worth 46 pointsComplete the Showdown Tour with at least a Silver in every event The Bronze! achievement in DiRT Showdown worth 46 pointsComplete the Showdown Tour with at least a Bronze in every event