Longhurst made his Bathurst 1000 debut in 1983 in a self-entered car alongside Mike Burgmann. He joined Frank Gardner's JPS Team BMW for the 1984 Australian Endurance Championship, beginning a long association with the German marque. Co-driving with Jim Richards, Longhurst continued with the team in 1985 and won the Sandown 500 that year as part of a JPS one-two finish. In 1985 he also entered three solo Australian Touring Car Championship rounds, finishing third at Amaroo Park. He contested the full 1986 ATCC, again placing on the podium at Amaroo and ending the season fifth in the championship. In 1987 he finished fourth in the championship with four round podiums. Gardner disbanded the team at the end of that season.
With the JPS team gone, Longhurst established his own outfit in 1988 based on the Gold Coast, backed by shareholders including Gardner and Terry Morris and supported by the Longhurst family's Dreamworld entertainment business. The team raced under various names across its existence — LoGaMo Racing, Freeport Motorsport, Benson and Hedges Racing — driven by changing sponsorship arrangements.
The team ran the powerful Ford Sierra RS500 from 1988 to 1990. At Bathurst in 1988 Longhurst and Tomas Mezera won the race, and the Sierra from that victory is preserved at the National Motor Racing Museum at Mount Panorama. Longhurst also won his first championship round that year at Amaroo Park, and demonstrated a particular affinity for Lakeside International Raceway, winning rounds there in 1988, 1991 and 1992.
The team switched to the BMW M3 Evolution from 1991 to 1993. Longhurst finished a career-best third in the championship in both 1991 and 1992. When the ATCC moved to a Group 3A formula based on Ford Falcons and Holden Commodores in 1993, the team initially continued with the BMW before switching to a Holden VP Commodore supplied by Perkins Engineering in 1994. Longhurst won the first race of the 1994 Barbagallo round in that car — his final solo championship race victory.
He also won five editions of the AMSCAR series at Sydney's Amaroo Park circuit, taking the title in 1986, 1987, 1989, 1990 and 1991 across BMW and Ford machinery. In New Zealand he won the 1992 Wellington 500 in the team's BMW M3.
Longhurst sold his share of the original team in 1995 and formed Longhurst Racing to campaign a Ford EF Falcon with Castrol backing. The team's strongest result in this period was a podium at the 1996 Bathurst 1000 with co-driver Steven Ellery. Despite promising moments the team found consistent results elusive, and Longhurst sold it at the end of 1999.
For 2000 he drove for Stone Brothers Racing. He came close to a second Bathurst victory that year alongside David Besnard, making the most pit stops of any competitive car but leading with ten laps remaining before an incident ended their challenge.
In 2001 he competed in the single-driver events with Rod Nash Racing before being drafted into the Holden Racing Team for the endurance rounds. Partnering Mark Skaife, Longhurst won the 2001 Bathurst 1000 — his second and final victory at the circuit. His 2002 season with Briggs Motor Sport was his last full campaign as a regular V8 Supercars starter.
Longhurst continued to enter endurance events periodically through the mid-2000s, including a spell with Perkins Engineering in 2004 and a purchased license with Team Dynamik in 2005. He announced his retirement after the 2005 Bathurst 1000 but returned as a co-driver for Steve Owen in 2006 and for Glenn Seton in 2007 at Sandown.
In 2009 he won the Bathurst 12 Hour alongside Rod Salmon and Damien White, joining a select group of drivers to have won both the Bathurst 1000 and the Bathurst 12 Hour. In 2017 he contested the Liqui-Moly Bathurst 12 Hour in a BMW M6 GT3 for BMW Team SRM alongside Timo Glock, Mark Skaife and Russell Ingall. The following year he won his class in the 2018 Bathurst 12 Hour in a GT4 BMW alongside Aaron Seton and Matthew Brabham. He subsequently retired from competition.
Longhurst also represented Australia internationally, competing in the 1987 World Touring Car Championship and the 1993 FIA Touring Car Challenge with BMW, and winning the 1994 Australian Super Touring Championship for the marque. He continues to live on the Gold Coast and manages the Boat Works marina facility at Coomera.