I filled the gaps between the doors and other body panels and the gap between the roof and the boot window.
I used 3M black sealing foam tape.
Here's the boot window gap (it still remains partly open, but will make a difference):
The tape is wider than the ridge at the doors.
I could have cut it narrow (it is easy to cut with scissors) but decided to just press it in the fold for added insulation., like here below the B pillar:
When closed you only see the side of the tape, flush with the panels:
After a few days the tape gets loose in some spots.
I prepped the underground with white gas (petroleum ether) and it did stick very well initially, but maybe the strip glue does not work well with moisture?
I may prep it with thinned glue when I get the chance.
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2011 Honda Insight + HID, LEDs, tiny PV panel, extra brake pad return springs, neutral wheel alignment, 44/42 PSI (air), PHEV light (inop), tightened wheel nut.

lifetime FE over 0.24 Gigameter or 0.15 Megamile.

"The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself.
Therefore, all progress depends on the unreasonable man."
George Bernard Shaw