Get both wiring diagrams for the Subaru and the Camry and see if the wires match up. Then you should get a decent idea if it would work before getting into it.
Or easier option might be buying/investing in a $80 aftermarket radio with the wiring harness that fits your car. Just my .02
Andy - 12 WRB WRX
Tuned by Innovative Tuning
294 AWHP / 311 TQ