I am a wondering if there is a recommended "best practice" for a product search SEO. I know to create a dynamic sitemap file that lists links to all products in the site. However, I want to implement a a bookmark-able "advanced search". Should I let search engines index any of the results? Take the following parameters for a search on a make believe used car website:

• minprice (minimum price in dollars)
• maxprice (maximum price in dollars)
• make (honda, audi, volvo)
• model (accord, A4, S40)
• minyear (minimum model year)
• maxyear (maximum model year)
• minmileage (minimum mileage)
• maxmileage (maximum mileage)

Given these parameters, there could be an infinite number of search combinations:

• Price Between $10,000 and $20,000
  • /search?minprice=10000&maxprice&20000
• Audis with less than 50k miles
  • /search?model=audi&maxmileage=50000
• More than 100,000 miles and less than $5,000
  • /search?minmileage=100000&maxprice=5000
• etc.

Over time, there may be inbound links to a variety of these types of searches, yet they are all slices of the same data. Should I allow for all of these searches to be indexed?