Unlocking a vehicle from GTA San Andreas, which is in .dff format, is very useful for converting it to GTA V later. However, the method is quite long despite its simplicity.
Now this method is certainly rather long, but not that complicated. Obviously it is not as fast as unlocking the vehicles of GTA San Andreas.
You will need several things which will be downloadable in the description of the video on YouTube.
The only downside to this vehicle unlock is the fact that we get it back in pieces, so obviously, it can be disturbing at first if you only start modding, but after with experience you will be able to glue back together the pieces to convert the vehicle to GTA V.
Remember to credit the authors of the original models you convert to GTA V if you publish them later.