No you don’t. I just installed mine from 5Star using the RTD4. Once you purchase a tune they will send you the RTD4. You plug that into the OBD2 port and read the stock file. That gets automatically sent to the tuner. Once the tune is ready (usually a few days), you will get an email at which...
I’m down to choosing between Wengerd and DRP Motorsport. I can tell you that I’ve been getting really prompt responses from DRP. I asked Wengerd a question at 11pm CT and got a response right away as well.