[1] He won the 2024 24 Hours of Nürburgring for Scherer Sport PHX, driving alongside Ricardo Feller, Christopher Mies, and Frank Stippler.

[8] As a result, Marschall moved to BMW Team Schnitzer for the 2018 ADAC GT Masters season, driving alongside Victor Bouveng.

The duo claimed two class victories, with Marschall starting the latter on overall pole position,[14] en route to a third-place championship finish.

[15] The entry claimed two class victories, at the Nürburgring and Jeddah, en route to a third-place finish in the Bronze Cup championship.

In June 2024, Marschall formed part of the Scherer Sport PHX team that won the shortest Nürburgring 24H in history, after over half of the race was red-flagged due to fog.