Born in Scarborough, Ontario, Heimrath started his driving career racing Go-karts and Formula Fords.
In 1979 and 1980 he won the Ontario Formula Ford Championship winning seven races in total.
The next several years, Ludwig competed in the IMSA GTP Series and drove a factory supported Porsche in Trans-Am.
Heimrath graduated as an engineer from Ryerson Polytechnical Institute (now Toronto Metropolitan University).
Ludwig is married to Kathy Rude, the first woman to win a major international sports car race, a GTU class win at 24 Hours of Daytona in 1982 with Lee Mueller and Allan Moffat.