wheel controls work on after market you just get a convertor box thing
my one is this
https://www.dynamicsounds.co.uk/conn...RoCiQMQAvD_BwE
but yours may be a different model
personally I would vote for new stereo, touchscreen, android auto for maps etc, reverse camera if you want it, bluetooth for music and calls, a better amp built in .. you might have the under-seat amp which changes things slightly but mine sounds so much better than original (which was only off the head unit)
I also put twin 12's in the boot but that's optional of course