I will try to help ...
You need to add the following nodes in the vehicle heirachy in unity for p_on, p_broken and p_damaged like shown in the picture below (Pic1).
These nodes are referenced in the standard engine xml node in vehicles.xml already, although on newer version of the games vehicles.xml TFP now group all of these nodes under one parent Particle node (Pic 2).
Pic1
Then under each of these nodes add your particle effects of choice .... the ones we use in Vehicle Madness are combinations of some we made ourselves and some that we downloaded from the unity store.
Pic2
Hope this helps !!
If you need more help then i recommend you join the unnofficial community modding discord, we do have people from all over the world that are happy to help !
Information on how to join is here ... Unnofficial Modding Discord.
Regards
Ragsy !!