Opel Vivaro 2.5 dti, 2006, self-heating installation Planar 2d

Moin people, I’m addressing you because I’d like to hear my opinion. I finally had a planar 2D and the anticipation is huge. Now, of course, I’ve already dealt with various videos with the topic and now I have 2 questions…. No1. Since I have a station wagon, I play with the idea of placing the heater under the passenger seat, does someone have experience with it or consider? Better ideas? Since I need the full cargo space floor this doesn’t come about in question… No2. The question with the fuel, someone happens to know ΓΆb my 06er vivaro has a diesel run back? Think this is the best solution for me, because easy to realize. I would be very happy about your opinion! Greetings go out!