Since no-one was up to the task I decided to upload the lost Project From the Past Vehicle Pack created by Unopescio for GTA III and then GTA IV. The pack brings original vehicles from Grand Theft Auto III remade in HD universe to the streets of Los Santos (or Liberty City if you wish to). 

Included Vehicles:
Banshee
Mr.Whoopee 
Landstalker 
Diablo Stallion
Stinger (Normal & Yakuza variant)
Cabbie
Borgnine
Sentinel (Normal & Leone Mafia)
Echo (Normal, Taxi, Police, and Beta Police)
Manana
Kuruma (Normal & FBI)

Installation:
mods > update > x64 > dlcpacks > drag the folder "frompastcars" here
add this line to the file dlclist.xml in update.rpf: <Item>dlcpacks:\fromthepastcars\</Item>

Spawn Names: whoopeeold , landstalold, diablosold, yakuza, cabbieold, bansheeold, mananaold, mananaold2, borgnine, mafiaold, sentinelold, stingerold, cabciv, policeold, betapolice, taxiold, echoold, kurumaold, kurumafbi

Yes, many models come with limited bugs due to the unfinished state left by the author when the project was discontinued. I plan on updating the pack in the future to include more vehicles, proper handling, and quality compatibility with V's mechanics.
All credit for the models and ideas allocated to the original author (Unopescio) & Rockstar Games. Please contact me if you wish to upload to any other websites, however feel free to leave videos and reviews here to demonstrate the content to other users. Thanks and enjoy!

