Just as she'd planned, Sinead O'Connor tied the knot Thursday (her 45th birthday) with fiancé Barry Herridge. But the singer said "I do" in quite the non-traditional fashion – while sitting in the back of a pink Cadillac.
"She wanted to do the whole thing in a Cadillac. That was her thing," a source tells PEOPLE.
Arriving around 7 p.m. in a pink, low-cut dress that revealed her tattoos, the "Nothing Compares 2 U" singer filled out paperwork before settling into the Caddy at A Little White Wedding Chapel on the famous Las Vegas Strip.
"It wasn't a traditional dress, but it wasn't a traditional wedding either," says the source. "She cried during the vows and had to wipe her eyes."
After the ten minute ceremony, O'Connor and her new husband – who donned a dark jacket and pink shirt – lit candles as employees of the chapel sang "Happy Birthday" to the bride.