[rpmerf]

Unless the carpet is really bad, you could try to shampoo it. I got a house shampooer for about $120 and it has worked amazing. In the house and in the cars. Decent investment if you have carpets in the house, especially if you have kids or pets. The cheaper route is to use a spray bottle or pump sprayer - soak it down, hit it with a brush, and suck it up with a shop vac. It's more about getting it wet and sucking the dirty water off than it is about scrubbing it.