As I have allergies, this is one of the most important additions to our rig yet. Reason being, built in vacuums dump the spent air outdoors, not recycled back inside. I don't care how great they say filtering vacs are, my sinuses say something different.
Here's where I parked the main unit. It is a Eureka I got on EBay. Note the outside vac attachment. Great for vacuuming the car, bays, dogs, etc. The spent air dumps into the center of the RV frame area. Hardly hear it running.

The interior hose adapter and the nifty toe plate accessory. When you kick the lever, it opens a hole and turns on the vac. This way you can just sweep the debris into the hole if you just want to do a quick clean up.