To install the car open openiv then press ctrl and f3 at the same time to open search bar, then you search for "dubsta3.yft" and double click on it, you will come to a folder with dubsta3_hi.yft and dubsta3.yft then you open the YFT files folder from winrar and replace the car, you could go to YTD fildes and replace it aswell, but is not necessary
 or you can go to x642>dlcpacks>mphipster>dlc.rpf>x64>levels>gta5>vehicles>mphipstervehicles.rpf and replace from there

To install textures press ctrl f3 again and search for dubsta3_hi.ytd and press the highest one, you should come to a folder with texture files only, replace the dubsta3.ytd from YTD files.

To install handling file which is optional, it gives the car realistic handling, handling was from https://www.gta5-mods.com/vehicles/off-road-and-main-character-vehicle-handling-suspension-speed-deformation 
Go to x64w.rpf\dlcpacks\mphipster\dlc.rpf\common\data and replace the handling file in there
