Ultima GTR (replace + add-on) for GTA V by "elcreador"
This mod replace futo.
Conversion from assetto corsa and adapted to gta v.
Thanks to WTC chiz and Michel for his friendly advices.
It is recommended that you use OpenIV's mod manager feature (http://openiv.com/?p=1132) with rpf mods to provide easy switching of rpf mods to off for online play to avoid bans.
Instructions into the folders.
I use a simple trainer with an script to prevent that the cars disappear.