Usually he doesn't do soundcheck except a few occasions, so he arrives at the venue around 5 PM, I think.
When I met him when Beady Eye played at Paradiso in 2014, he arrived together with Gem, Andy, Chris and Jay by a touring bus and he took time to meet his fans. After soundcheck he left with Debbie by a car. I said this more than once, but Liam was really nice and kind. I never expected he would be like that to be honest. He's one of the nicest musicians I ever met.
Last year when he played in Amsterdam, he arrived in the venue after the door was open and his car went straight away to the parking lot. I was already inside the venue, but my friends were at the back stage door.
He will most likely get into a parking lot straight away, but you never know. It's just a matter of luck, I guess. Good luck.