The 61-year-old from Wolverhampton captured the hearts of the country when he wiggled his way to the finals of ITV's biggest talent show.
Despite missing out on being crowned the winner of the contest, the AA man is set to release his self-penned song as a single later this year.
WATCH Donchez's BGT final performance:
Speaking on ITV show Lorraine on Monday morning, he said: "It's going to be out very, very soon."
The singer from Penn managed to win 11.2 per cent of the final vote after his mash-up of songs 'I Am Only a Man' and 'Wiggle Wine' saw him finish in third place in Sunday night's final.
He was beaten to the top spot by Lee Ridley, better known as Lost Voice Guy, who scored 21 per cent of the votes during the final.
Father-of-four Donchez said he 'appreciated' all the messages of support which have flooded in since his first audition, which saw judge David Walliams slam the golden buzzer and send him straight to the live semi-finals.
"It's been a rollercoaster of a fantastic journey. From the first audition, progressing on to the whole thing, and the whole team of BGT staff and the way they make your dreams come true is something else. Fantastic.
"It was full-on. I was so conscious on the stage in front of the judges, I do get excited. Sometimes I want to calm it down.
The AA mechanic also revealed he wants to pursue music full-time and has a Christmas tune ready to hit the charts.
He said: "I have backed up two albums, a devastating Christmas song ready to go, a Christmas party just waiting.
"I can't stop writing. I got a novel together, because one of my songs, my brain wouldn't switch off from writing the song, so there's a novel, a book ready to release."