I got this installed Yesterday at Tweeters in Riverside. I was the 4th Prius they have worked on and their 2nd Amp upgrade install. My two installers were Jaion and Jason. They built me a Custom Fiberglass box to fit between my trunk lid and wheel well. They added an Alpine F450 5 Channel Amp and 8" JL 75w 4ohm Sub. They integrated the stock amp with my new one. I didn't lose one feature. My sterio dims when I get a phone call or use voice commands. I can control the fade and balance from the MFD. Everything works just as it did but now sounds a whole lot better. They did a great job and it sounds really 100% better than it did. An interesting side effect, The beeps made by the MFD when you press a button are now amplified. :| I don't mind it.. But It wasn't expected it. Anyways, Here are the photos. http://www.priuschat.com/forums/album_pic.....php?pic_id=942 http://www.priuschat.com/forums/album_pic.....php?pic_id=943 http://www.priuschat.com/forums/album_pic.....php?pic_id=944 http://www.priuschat.com/forums/album_pic.....php?pic_id=945 --- Cost Breakdown --- Alpine F450 Amp - $499 JL 8" 75W 4ohm Sub $65 Monster 4 Channel RCA's $80 Monster Fuse Holder 4/8 gauge $25 Monster Fuse 4 Pack $7 4 Gauge Monster Blue Power Wire 5ft $10 8 Gauge Monster Silver Ground Wire 5ft $5.50 Amp Install Labor $75 Integrating Nav and Phone Labor $50 Custom Fiberglass Box $250 + tax 7.75% and I don't think they charged me for that blue box under my seat. ??? I'm not sure. And I thought 250$ for the box was a good deal if you saw what they had to do to make it. One guy worked on it for 5 hours. And they used at least 80,90$ in supplies. It fits perfectly and is just enough space for an 8" sub. They said its just about 1/2 cb ft of space.. Witch is optimum for the 8" sub I got. -----Total ----- Aprox $1150 Not bad. I'm still planning on upgrading the component speakers in the front and rear. And since the stock head unit doesn't have a sub control I want to add a device that will allow me to control one. I wish the carpet would have matched a little better but it was the closest thing they had. I might buy some factory carpet from Toyota and have them fix it when I get the components installed next month. So here it is. I've read so much talk about how hard it is to add an Amp in the Prius. I don't think it was hard at all. Mind you I didn't do it. So of course it wasn't hard for me. But it can be done and it sounds great when it is. I'm really happy with the job and the system. Most importantly, It looks clean, and sounds balanced.