In October 2013, Muir announced that he would form a voting bloc in the Senate with the Palmer United Party's members.

He joined the Shooters, Fishers and Farmers Party in 2017, standing unsuccessfully in the seat of Morwell at the 2018 Victorian state election.

[4] Muir said that as a young man, he was interested in customising cars, but as he gained a family, he moved on to four-wheel drives as a way to explore the countryside.

Independent Senator Nick Xenophon and larger parties including the incoming government are examining changes to the group voting ticket system.

[16][17] In an interview by Mike Willesee broadcast on Channel Seven's Sunday Night program on 8 June 2014, Muir was shown to have considerable difficulty explaining the meaning of the terms "balance of power" and "aftermarket".

[20] Muir also hired former New South Wales state politician Peter Breen to advise him on legislation,[21][22] but also sacked him on 6 August 2014.

[24] On 19 November 2014, Muir voted against changes to financial planning laws on which the Abbott government and Palmer United Party had reached agreement.

[29] He contested the electoral district of Gippsland East at the 2022 Victorian state election, coming fourth with 5.83% of the vote.