Retrofit Renault Trafic II Evado air heater

Dear community, I need your help again. As in the description, I have a Renault-Trafic Evado II with a second battery under the driver’s seat. I want to retrofit an air heater. I really want to mount it outside. The effort between inside and outside seems similar. Outside, however, I have the advantage of saving space and possibly hearing less noise. I think I prefer to operate it with fresh air, not in circumferential air operation. n should of course be permanently installed, for a mobile installation would probably rather offer itself inside. I need an approved heating. I found this here: https://www.g-part.de/LF-Bros-E50-3KW-12V-Kit-EU-Version The well-known manufacturers are after all again considerably more expensive. If I would install them in mobile, however, can I also take the 100€ China-Dinger or what is your opinion about it? But also in this case I would have to drill through the base plate n to remove the exhaust gases directly and to tap the diesel feed, because I can only transport closed spare canisters, right? Now I have some general questions: Has any of you ever installed a heater in the Trafic in the one or other variant (where, like air supply/disposal, diesel feed) and can possibly help me with some photos (where I would of course ask even more specifically, WHAT interests me)? Of course there are already many contributions and endlessly he forums, I know. I am particularly interested in Evado, because it seems to be installed from the factory INNNEN, but with many other models more often outside – at least I have the feeling. I would be interested in two things in particular: When I drill through the floor plate (rail system), do I have to take out the floor covering first? How do you let the air flow into the passenger compartment during outdoor installation? Do you have an extra nozzle installed? Where? I thank you for your opinions. Greetings and a good day to you! Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon, Simon