is there any way at all to use keyless with an aftermarket stereo ? seems a bit odd
Yes. But you must still have the stock radio too. You may still have it. Pull your center counsel apart all the way down to the cup holders and you should see the stock head unit still wired up there (just the power). If its not there you'll have to buy one, I found one at my local pull-a-part. After that grab your remote ad follow these steps
1) Turn Ignition to On, but do not crank car
2) Within 10 seconds, press and hold the valet button (Slim button b/w the AM-FM and CD-Tape buttons)
3) While holding valet button, listen for the door actuators to activate
4) Continue holding the valet button and press a button on your remote
5) Still holding valet button, lister for actuators to activate again
6) While holding the valet button, turn the key all the way back (off)
8) When the car is turned completely off the radio may flash (the screen would have been blank the whole time)
7) Remove key and test remote
REMEMBER: You cant let go of the valet button at all during the process.