You will need the following to add the trip computer to your vehicle.
Trip computer - I got one from the classifieds for $150. 00 w/console(console now a spare) plus mine had the upper harness.
Temp sensor - #4688204 $16. 10
Temp sensor jumper wire - #56021994AB $21. 60
Upper harness (inside console) - #50130608AA $32. 85
Lower harness (from console to fuse box) - #56045921AC $57. 45
I don't know how much the trip computer costs or its part # as I got mine used. Works great I missed the Temp and compass from my 96'.
Cost me around 300. 00, just have to determine if its worth the cost. Dealer wanted around 1800-2000 for the install.
Check the junk yards, should be a few more in there now than there was when I was looking. You could get everything from the same place.
lol