I am using ROCKnMARS 7" system which costs around 10k and it have dvd player, BT/FM/IR/USB etc. GPS supported system costs around 20k which have NAVITEL maps (But i prefer Sygic more)
I was also looking for some cheap portable yet best navigation system for corolla. I did a LOT of research in the market and over the internet. Corolla is selling navigation very costly. Then I found following other options.
1- V7 2d/3d navigation system (its a hardware device like tablet , based on SYGIC GPS navigation) available in 4/5/7 inch screen, costing around 8k to 15k depend on size. Offline GPS navigation supported. Home delivery available, There site is following.
V7 Traders and https://www.facebook.com/v7trader
2- You can also buy some china base 7 inch Tablet like airtel airpad which costs only 7,000 Rs (deliver at door step via megabrands) and install sygic in it, and also purchase Car holder and charger to make it fit on windscreen or dashboard or where you like it to be.
3- Use your existing android mobile and install SYGIC maps (Currently I am using this option and believe me using this app, I was able to visit places in Karachi where I even cant think of going alone dueto my poor capability of remembering routes, it gave me lot of confidence.
I am using Sygic 14.7.4 version and its very good, it can guide you with map/voice guidance turn by turn , speak road names using TTS, etc etc. I have ordered airtel 7 inch android tablet and it will be in my hands by this saturday. then I will install sygic, test it, and post some snaps here too
Youc an see all Sygic Features here.
Snap of its usage on my Samsung galaxy s3 android phone are as follows