Would a 5 gallon wet dry vac be a good size for cleaning the interior of a car? My car is brand new so I want to keep it that way by vacuuming the carpets every couple of weeks. When I had my tib I always just went to the pay vacuums at car washes to do the interior. I saw they have 3 gallons but I think that may be too small.

 

Consider how many gallons of trash you will be vacuuming out of a clean car. Smaller is easier to kick out of the way/walk around in a shop. Be more concerned with user reviews on performance than just size.