If you have installed any vehicle mods, make sure that the .ytd and .yft files don't exceed 25mb per vehicle.
For example, if you replace the main police car, and the files are police.yft - 13mb, police_hi.yft - 1mb, police.ytd - 15mb, then that vehicle will be taking up 29mb of space.
GTA V has a soft limit of 25mb allowance per vehicle, so anything over 25mb will cause texture loss.
Using OpenIV, go into the .ytd file and export all of the textures, then resize the largest ones (a lot of vehicles have 4k interior textures - why??)
This video is a great guide: