In 2017 Estep made his transition from open wheel to cars in the North American Porsche GT3 Cup Series,[7] with JDX Racing.

[28] Estep made a one-off appearance in Redbull[29]Global RallyCross[30] with PMG Rallysport[31] replacing Parker Chase at the Wild Horse Pass Motorsports Park in Chandler, Arizona.

Estep received the last minute opportunity just days before the event only having 4 laps in a business parking lot to fit seat and test radio before leaving for Arizona.

He competed against an international field including European World Champion Jordan Lennox-Lamb and Canadian Indy Car driver Zachary Claman DeMelo.

2017 - After receiving 22 offers at the end of 2016 to compete in various series including Porsche GT3 Cup, Lamborghini Super Trofeo,[32] USF2000,[33] Pro Mazda,[34] US F4,[35] Formula Atlantics,[36] Pirelli World Challenge,[37] IMSA Lites,[38] and F2000.

[39] After a great deal of consideration Estep signed a contract with JDX Racing to run in the IMSA Porsche GT3 Cup Challenge Series.

2021 - He ran at the 12 Hours of Sebring in GTD with Team Hardpoint EBM Racing pairing with Rob Ferriol and Earl Bamber.

2022 - The start of 2022 Trenton won the Pro-Am class co-driving with Mark Kvamme at the Gulf 12 Hours at Yas Marina Circuit in Abu Dhabi in an AF Corse Ferrari.

2023 - Trenton will be running a limited schedule in IMSA in GTD Pro for MDK Motorsports and a full season in SRO Fanatec World GT Challenge with his co-driver Seth Lucas.

The year started out at the Rolex 24 Hour at Daytona where he placed 4th in GTD Pro driving with Mark Kvamme, Jan Magnussen and Jason Hart.

(key) (Races in bold indicate pole position; results in italics indicate fastest lap) † Points only counted towards the Michelin Endurance Cup, and not the overall LMP3 Championship.