Not very professional work. I hope you sent that to the service manager.
I don't know for sure either, but it does look to me like the duct goes right under the inverter. Although the blower seems quite large for that job, so there might be more to the story.Don't have a visual reference and too lazy to go look at mine, but I believe that fan would be to cool the DC to DC inverter for the 12V battery charging system. It may also be used to cool the amp for the subwoofer if you have the Bose upgrade.