We tested a bunch of the top car vacuums available to find the best:
To test the noise levels of each vacuum, we set up a decibel meter an arm's length away. We then ran each vacuum at maximum power for 30 seconds. Interestingly, larger did not always equal louder.To determine maximum suction readings, we purchased a vacuum meter that measured inches of water—essentially, how much suction power the vacuum's motor makes.
Cars, particularly family cruisers, can accumulate a wide variety of dirt and debris, and every single small-mouthed crevice tool simply got clogged up by big chunks—usually by the Cheerios. The prices ranged from $40 to $450, and the sweet spot seems to be right around $100. It all depends on what you want from a car vacuum—for us it's power, performance, and versatility—and the price will reflect that.
If you own an RV or motorhome, a stick vacuum might be the way to go. They're fantastic for these because of their versatility, and they're portable enough to pack.