Starting off in karts at the age of 8, by 1996 Susie was named British Woman Kart Racing Driver of the year. The following year she contested numerous categories and came out top in several of them. In addition to winning the 24hr Middle East Kart Championship, Susie won both the Scottish Junior Intercontinental "A" and Scottish Open Junior Intercontinental "A" categories and was once again named British Woman Kart Racing Driver of the year.
For 1998 she moved up to the British Junior Intercontinental "A" Championship and was placed tenth overall in her first season. She also competed in the Federation Cup European Intercontinental "A" Championship and she was placed eleventh overall. For the third year in a row, she was named British Woman Kart Racing Driver of the year.
In 1999, she competed in the British Formula "A" Championship and was placed thirteenth overall. She also achieved thirty-fourth overall in the Formula "A" World Championships and again was named British Woman Kart racing driver of the year.
2000 saw her improve on her previous performance in the British Formula "A" Championship where she came tenth overall this time around and she also improved on her previous performance in the Formula "A" World Championships where she was placed fifteenth overall. She also won an award which named her as the Top Female Kart Driver in the world.
In 2001, Susie made the switch to single-seaters, contesting the 2001 Formula Renault Winter Series with the Motaworld Racing team. The following year she made her debut in the full Formula Renault UK Championship with DFR Racing, while again contesting the Winter Series with Motaworld.
Remaining in the Formula Renault UK Championship in 2003, she scored her first podium finish, ending the season ninth overall. In recognition of her efforts Susie was selected as one of the finalists in the prestigious BRDC McLaren Autosport Young Driver of the Year Award and also selected as the BRDC Rising Star of the Year.
2004 saw her contest her third season in the Formula Renault UK Championship, this time racing for Comtec, the youngster finishing fifth overall with three podium finishes during the year.
For 2005, Susie made the step up to the British F3 Championship with Alan Docking Racing however, her season ended after just five races due to an ankle injury sustained over the winter. She also made a one-off appearance in the Porsche Carrera Cup GB at Brands Hatch.
For 2006, Susie made the move to the legendary German Touring Car series DTM, driving a 2004-spec Mercedes-Benz C-Class Coupe for the Mucke Motorsport team. In her debut season she achieved a best finish of ninth overall in the final round of the season (Hockenheimring).
In 2007 she remained in DTM series, driving a 2005-spec Mercedes-Benz C-Class Coupe for Mucke Motorsport, her best finish coming at Mugello where she finished tenth.
For 2008 she joined Persson Motorsport, where her teammate was Gary Paffett, her best performance coming at the Norisring where she finished tenth.
From 2009 to 2012 she remained in DTM, still with Persson Motorsport, her best season being 2010 when she finished thirteenth overall courtesy of sevenths at Lausitz and Hockenheim.
In 2011 Susie married former racer Toto Wolff, who since 2009 had been a shareholder in the Williams F1 team. A year later the Scot was announced as development driver for the Grove outfit, her main focus being simulator work and aerodynamic tests.
Having made her F1 test debut at the end of 2012, in 2013 Susie took part in the Young Driver Test at Silverstone, thereby becoming the first woman to take part in a timed session since 1992. Finishing ninth overall on her one day of driving, Susie's best time was only 0.977s off (teammate) Pastor Maldonado's best.
On 24 February 2014, Susie was named as Williams development driver for the forthcoming season, her "expanded" role to include two Friday (FP1) sessions over the course of the season.
"From the age of 8, I was racing against drivers such as Lewis Hamilton, Nico Rosberg, Robert Kubica and Kimi Raikkonen," she declares on her website. "Every driver starts in karting and moves up the ladder with the ultimate goal always being F1."