You will probably have to buy the mounting kit from Sunset, Eagle Day, or Suncoast.
The windscreens occasionally show up on eBay and craigslist for like $50-100, or try calling a Porsche dismantler / salvage yard. In my opinion though don't waste your money on the black plastic mesh inserts there useless, and decrease rearward visibility, but the plexiglass windscreen is worth it.
:dance:
Hope this Helps!