This must be a script mod
Script should check if vehicle is upsidedown / vehicle do rollover
then use the Player's duck native to duck.
@Remourz For example what two cars have your tried to install that cause a problem? With an Addon for me anyway the joy is that you can have two cars plus at the same time.
Looks like your connection to GTA5-Mods.com Forums was lost, please wait while we try to reconnect.