However, Formula Renault UK employs a points system that means that a driver must drop their two worst scores over the season.

Unfortunately for Sims, his worst scores were a pair of ninths worth 24 points, and Adam Christodoulou, his main championship rival dropped two retirements.

[13] He also contested the final round of the Formula BMW Pacific in Macau, finishing eighth with the fastest lap.

[15] At the 2008 Autosport Awards ceremony, Sims announced his plans to race with German team Mücke Motorsport in the Formula 3 Euro Series.

He joined Hexis Racing in 2013 to compete at the Blancpain Endurance Series with a McLaren MP4-12C, partnering with Álvaro Parente and Stef Dusseldorp.

The Brit competed at the 2016 Blancpain GT Series for Rowe Racing with a BMW M6, winning the 24 Hours of Spa.

Sims competed in two races of the 2018–19 FIA World Endurance Championship for BMW Team MTEK.

At the final race of the season at the 2019 New York City ePrix Sims claimed pole position and the first podium of his Formula E career finishing 2nd.