Dhanush has gone out of his way to endorse Udhayam NH4.
The reason is that the film is produced by his good friend and Aadukalam director Vetrimaran and Dhyanidhi Alagiri.
Udhayam NH4 originally was written by Vetrimaran keeping Dhanush in mind. But due to other factors finally Siddharth did the role. It was one film which Dhanush wanted to do but never happened.
A day before the films release Dhanush has tweeted, "Udhayam NH4`s script is very close to my heart. Me and Vetrimaran lived with it for more than 5 years. Now finally it has come to life, can`t wait 2 see it."