Best way to install textures to have every car variations

Hi all.

Well, first of all, sorry if this has been discussed before. I have expend half and hour looking around on this forums and couldn't find any relevant info about this.

So here is my doubt so maybe some of you have found a correct way to do this.

I've download and installed several vehicle mods and textures from them. Of course, ranging from LSPD to LSSD, with some CHP variants around also.

I know how to use OpenIV, editing and so on. That's not a problem.

My question is, what's the best way to install all of this textures in order to have all of them available when going on patrol? I've tried changing the trainer to change the texture of the vehicle, but no success. I would like to have them better placed and be ready for the new LSPDFR update in which you'll be able to set your own custom backups (so you can call Sheriff, CHP or whatever you thinks is more situable)

The current mods I've installed are (taken from @Jeff Favignano videos, thanks mate!) :

2012 Ford Police Interceptor by POLICESCO - http://goo.gl/x3EhZQ
2015 Chevy Suburban by POLICESCO - https://goo.gl/0fW9cb
LAPD CVPI by POLICESCO - https://goo.gl/yrOXdN
LASD CVPI by thegreathah - http://goo.gl/22Vk3y
Unmarked CVPI Pack by NIGHTKID - http://goo.gl/wDM7Kk 
LAPD Ford Explorer - http://goo.gl/f48FdQ

And some texture packs (same source, of course):

LSPD CVPI Textures - http://goo.gl/v9UVoM
LSSD CVPI Textures - http://goo.gl/Ta6yWL
LSPD/LSSD Tahoe Textures - http://goo.gl/eQ9RiT
LSPD Impala Textures - http://goo.gl/gWCmvU
LSSD/LSPD Explorer Textures - http://goo.gl/lRPjNP
LAPD/CHP 4k Explorer Textures - http://goo.gl/UdBssS

Actually my game is a mess and I have a combination of default and modded vehicles (I think I miss editing some of the dlcpacks files instead of just x64e) but, before reinstalling everything, I would like to know if some of you have some nice workaround for that and the best way to make it work.

Best regards,