After a long brainstorming, aftermaths, trying out various permutations combinations to get good quality sound from the OEM head unit finally i designed a circuit to use good quality sound from my IPOD/MP3 player/ android handset etc + keeping OEM head unit as source too. Result : Amazing sound quality of IPOD, perfect bass + satisfaction. Demerits : 1. No Fader control. 2. Steering controls do not work with IPOD obviously. Bill of Materials: 1. 3.5mm to RCA cable (MX) - 5 metres - Rs.150 2. Female to Female RCA splitter - 2nos - Rs. 40 3. High quality 99.1% oxygen free RCA cable (MX) - Rs. 150 4. Y cables - 2nos - already had it with me 5. High to low converter - 1/2nos depending on no of channels you want - already had it with me 6. Patience : a lot Long back in my old car i had tried to connect the mp3 player directly to the amplifier on similar design. it worked but caused a lot of hissing. so i had dropped that idea. But after couple of years this idea again started playing in my head, and for this i would thank our electronics guru Jayadev. he recommended to try it again with good quality cables to avoid hissing. His knowledge about electronics is simply great - the best DIY from him was the RCA hack from OEM head unit. i am going to try that too. I had a good quality sony mp3 player that i had got from US last year. it came handy today to provide very very very good quality of sound. i pulled a 3.5 mm to RCA cable from near the handbrake to the boot. The RCA cables i used are very high quality shielded ones. Due to this there is no hissing or popping sound whatsoever. instead of putting it in words i would like to present the wiring diagram- which looks complex but yes it works like a charm. Now whenever i have a mood to listen to good quality sound (which i always have) i play through the mp3 player and whenever i use phone thru blue and me or whenever i feel i want to use steering controls more i play thru OEM head unit (which sounds bakwas as compared to MP3 player source) the MP3 circuit provides very high quality PRE AMP signal to the amplifiers. i get option of good 5/7 band equalizers to play with + preset sounds.