After market NAV pack

I have a lease for a 2012 Prius. I'm thinking of buying it when the lease is up. I like the car. When I purchased it, the NAV pack with an audio upgrade was bundled with a moon roof and 17 inch tires. I didn't want either so bought a NUVI. I'm wondering if Toyota has an aftermarket NAV pack available? The NUVI works ok but I'd prefer something built in. Also, an upgrade on the audio system wouldn't be a bad thing.