ROFL... you're gonna love this, Perez. Maybe! LOL
Investigating the database, it appears the underlying problem is (and please don't take this as anything more than a joke...) impatience and greed!
You appear to have ONE HUNDRED AND FORTY NINE vehicles stored in the garage system. All of which are in fine, AOK, tip-top condition, just waiting to be taken out for a spin. Here's a quick summary of them all:
96 C_Offroad_01_F
21 B_Quadbike_01_F
10 C_Hatchback_01_sport_F
9 C_Hatchback_01_F
2 I_Truck_02_covered_F
2 C_Boat_Civil_01_F
2 O_MRAP_02_F
1 O_Truck_03_covered_F
1 C_SUV_01_F
1 O_Heli_Light_02_unarmed_F
1 C_Van_01_box_F
1 B_Truck_01_box_F
1 O_Truck_03_transport_F
1 B_Truck_01_mover_F
Ninety-six Offroads is a LOT of wheels, LOL!
I guess what's happened is that due to your slow internet connection (I'm guessing - because this doesn't happen this often or this repetitively to too many people, or I'd be inundated with reports), the garage-system took its time to display your first set of vehicles one day - and possibly even timed out completely. So you bought more vehicles and carried on playing (perfectly logical approach, tbh, and this isn't a criticism). But this in turn, meant that there were even more vehicles waiting to be displayed on your garage menu, making it even slower to load; and so on, the process repeated - until eventually, there is little hope that the garage-system can receive that many vehicles in the time allowed for the display to populate. And quite possibly, there is an upper limit on the number of vehicles that can be placed onto the display-window, in terms of amount (regardless of time taken). Not sure!
Not quite sure where we go from here, but it does seem that the database IS at least receiving your instructions whenever you buy a new vehicle and sync your data... so you've not LOST anything. You just can't get it all displayed again when it's time to re-use it! LOL. Cold comfort really, I know... but I guess you could try a couple of things... Firstly, go to a garage, tell it to display the vehicle list, and just wait. And wait and wait and wait (best not to do this in Kavala, or you'll be killed, no doubt!). See if the window EVER gets populated with data, or whether you get any kind of error message or change in state worth telling me about.
If you DO get a displayed list (eventually), maybe sell one vehicle and (again) wait, wait, wait, until the display comes back refreshed after the sale. Repeat until the number of vehicles owned is a more manageable size - by which time (fingers crossed) the display rate *should* have speeded up.
Failing that, if that's too tedious or just doesn't work, I guess I could try simply deleting a bunch of vehicles from your stored list above, and compensating the cash back to your account (you'll have to be offline while this is done, though, or your live data will just overwrite it all again and banish my changes I'm making via the back-end). The pain in the arse bit for me is working out what the compensation costs would be per vehicle - that's a lot of manual looking up I'll have to do to find the appropriate vehicle sale prices... but it's there as a last resort. If we go that route, I'll also need to know from you (nearer the time, not now) exactly what vehicles you want to keep most of all, so we can sell the rest and bring your vehicle numbers down to say, five or ten or something manageable.
Let me know how you get on with the first method, first, though.