I’ve already submitted a Support Ticket about the issue but I’ll share the issue here in case anyone knows a solution or is stuck with the same thing.
The problem started last night (14th March 2019) after joining and completing the Seasonal Playground Games Series.
Prior to the Series, I was enjoying my vehicle in Freeroam. Upon joining the Series I used the Hire car and when the Series completed I was returned to Freeroam and my previous vehicle. However…
…the particular vehicle has completely disappeared from my in-game garage. The in-game statistic for how many vehicles I have is correct but the car itself cannot be seen or selected (even if I’m currently in it). The vehicle does re-appear however if I enter an event and need to choose a car.