Your problem (I assume) for the French approval is the lack of EMC certificates for the motor and controller. Without these any EU country is not allowed to approve a converted car so getting something from a neighbouring country wouldnt help you.
Getting these EMC certificates is possible by doing a test but expensive. Looking at your build I believe you need to do some alterations before even considering taking these test.
Futhermore or besides the EMC test your HV wiring should be colorcoded (orange) and shouldnt be possible to touch so theres another 'finger-test' for that you have to comply.
I dont think you will ever get or pass these tests without spending a little fortune (>10.000 euro).
There is another option you could consider: get rid of the approval or 'car' status at all and 'register' it as a farmtractor or slow-moving vehicle. You wont need a registration or licenseplate for that but then your only allowed to drive a max speed of 25kmh. This could be 'tricked' though by programming your controller with some little switch to toggle between 25kmh/50kmh somewhere although it be illlegal...
Getting these EMC certificates is possible by doing a test but expensive. Looking at your build I believe you need to do some alterations before even considering taking these test.
Futhermore or besides the EMC test your HV wiring should be colorcoded (orange) and shouldnt be possible to touch so theres another 'finger-test' for that you have to comply.
I dont think you will ever get or pass these tests without spending a little fortune (>10.000 euro).
There is another option you could consider: get rid of the approval or 'car' status at all and 'register' it as a farmtractor or slow-moving vehicle. You wont need a registration or licenseplate for that but then your only allowed to drive a max speed of 25kmh. This could be 'tricked' though by programming your controller with some little switch to toggle between 25kmh/50kmh somewhere although it be illlegal...