I am not saying that you can do all the modifications on your own. Some changes I did which would have pictures here include purchased products. Wherever I can, I would purchase local products. If none was available, such as alloy bolts, I would go online.
One of the earlier enhancement which I did was accidental. The 4-2-1 header (or exhaust manifold) came with the car uninstalled. There were many ‘un official’ reasons for this of which I shall not deliberate. After approximately 3 months of ownership I found the 3rd port flange having a pinhole puncture. I diagnosed this to be impurities hidden inside the weld joint. I was denied warranty claim after I had it Mig Welded. So yes, it was my fault. I was ignorant as I never had a brand new car with 50k warranty. But I had a solution. I went to Powerzone in Glenmarie, Shah Alam. I ordered a new set of headers. These new sets were found to have a better design. It had a larger radius curve upon exit from the port. The tuned length made way for the air conditioning tubes and return hoses. Which made it a convenient purchase.
Now in retrospect, I have seen pictures of the 2008 Satria Neo R3. This is an article that appeared in a locally produced site Zerotohundred.com. If you scroll midway of the site, there is a picture of the header in that model. That has a smoother exit transition compared to the 2011 Neo R3 stock.