George, with the advent of electric cars, vacuum pumps that are designed to supply power brake boosters are common. As they are designed for a power brake booster application, they are usually a self contained unit with the appropriate pressure switches. I use one of these OEM vacuum pumps and stealthily hid it behind the driver's side headlamp. Hella makes a good one, which I believe is the same as the Audi pump. Summit has them in stock!