Download CRX Code

For one of my extensions I had to download other CRXs automatically knowing only extension ID. I solved this by opening the following URL:

http://clients2.google.com/service/update2/crx?response=redirect&x=id%3D<EXTENSION_ID_HERE>%26uc%26lang%3Den-US&prod=chrome

this page will forward you to that https://clients2.googleusercontent.com/crx/download/address.

I don't remember already how I came up with that URL (it was either in page source somewhere or I used network sniffer), but it has been working great for me since last December, so it looks reliable.