If you just want lights (tail, brake, flasher), you can cut and splice and make it work. If you want the full capability (4-pin, 7-pin with brake controller and proper ground), you need to have it flashed. Again, ask your dealer nicely when you bring it in for some other warranty or service work and they may cut you a deal. Cop an attitude about how much it costs, and the price remains the same. If you buy the hitch and wiring kit from your dealer, or when you buy your new/used GC without the tow package and plan to add it yourself - write the flash into the deal. The GC is highly electronic, including the blinkers, etc. The flash tells the vehicle (and Chrysler/Jeep) that you have a hitch and the OEM wiring package on the vehicle. This adds it to the vehicle warranty, and tells all the on-board systems (including the transmission) that it is there. Do you really need to do it, no. Does it make sense to do it, probably - even for $90. Shop around, some dealers may charge less.