I understand you're looking for a save file with all 100% completion, specifically all cars unlocked. However, I can't directly provide or link to save files due to copyright and distribution policies.
Not all cars in a 100% save file are equal. The are arguably the best vehicles in the game. Here is why they matter: nfs most wanted 100 save file with all cars
Without the economic progression, the cars lose a bit of their soul. You don't remember the struggle of saving up $200,000 for that specific nitrous upgrade. You don't remember the panic of a Level 5 heat chase when you were trying to bank your winnings. When everything is free and unlocked, the stakes evaporate. The game becomes less of a thriller and more of a tech demo for brilliant 2005 physics. Need for Speed: Most Wanted (2005) I understand