What do I need to make my navigation unit fit in my 2008 Yaris sedan?

[Cxltxn]

I'm relatively new here and a complete noob when it comes to anything to do with cars. I purchased a KW-NT300 JVC navigation unit and I have installed it and its working completely fine.

Only thing is that it doesn't fit properly where the factory deck was. This part says that it should be compatible but I've already ordered a similar part off eBay and it didn't work.

Height wise everything is fine, the unit is 4 inches and the hole is 4 inches but the width of the unit is about 6 3/4 inches whereas the width of the hole is about 8 inches.

I've done a search on here but I've been unable to find this information I'm looking for. I just want to know what I need to make this thing fit. It's possible that I'm not using the right terminology when I'm searching but like I said, I'm a complete noob when it comes to this.

I've attached a picture below:



Thanks in advance for any help!