I didn't. I bought an Eclipse AVN5510 from ebay about 1.5 yrs ago. I installed it myself and it works great. However, I've grown accustomed to using the steering wheel mounted audio controls on my wife's civic and I would like to add a steering wheel that has audio controls in my 03 matrix xr.
It's beginning to sound like this isn't an option for this car. I thought that the XRS's steering wheel might have had the audio controls. But now I'm guessing that one doesn't exist for the matrix.