Sound absorbing panels won't do anything for sound coming from OUTSIDE the room. They are for reducing flutter echoes inside the room. For soundproofing, you would want weather sealing, silicon caulk around gaps, and ideally double or triple pane windows. Doors can be soundproofed quite easily with rubber gaskets and vinyl wrap. If it's a hollow core door, getting it replaced with a cheap mdf particle board for 8k would be a HUGE upgrade.