I installed a Blaupunkt ..Melbourne SD-27.
It matches the interior well and is plug and play, with the exception of getting an adapter to connect to the stock radio antenna.
So far I've been happy with it except that it is very slow to change tracks (it doen't play CDs, it reads music from an SD card)
I picked it up for under $100 on ebay:

Blaupunkt Melbourne SD27 Digital media receiver | eBay

Hope that helps!