You followed the guide, but the DLC cars are still locked. Here is why:
This pack gives you the Aston Martin DB5 (James Bond) and the 1969 Dodge Charger R/T (Fast & Furious). Many generic saves ignore this.
A truly complete save file ensures every single collectible and event is cleared across the base game and all DLC packs: Single-Player Progress : All 61 standard events completed. The Blacklist
