Following establishment in 1968 and an initial period in national German series, Seikel moved into international competition in 1978 as part of Audi's campaign in the European Touring Car Championship. The team contributed to Audi winning the constructors' championship in 1980; Peter Seikel himself won the Group N drivers' championship in 1979. The team subsequently ran BMWs, Fords, and Toyotas in the ETCC until the series ended in 1988.
After the European Touring Car Championship was dissolved, Seikel was hired by Honda to develop the Civic for touring car competition and then campaigned a Honda NSX in the German national GT series. In 1994 Peter Seikel switched allegiance to Porsche and turned his attention to the newly created BPR Global GT Series alongside Le Mans campaigns. The team ran Porsche 968 RS and 911 GT2 machinery in the BPR and competed at Le Mans for the first time in 1994, retiring early with a DNF in LM GT2 class. The team returned annually to Le Mans, finishing 15th overall and fourth in LM GT2 class in 1995 and 18th in 1996. The BPR became the FIA GT Championship in 1997 and Seikel continued in that series through 1998, also earning class wins at the 6 Hours of Vallelunga and the 1000 km Monza.
From 1998 Seikel stepped back from the FIA GT Championship and concentrated on endurance racing. The team ran Porsche 911 GT3-R and GT3-RS machinery at Le Mans and in the American Le Mans Series and the Rolex Sports Car Series in the early 2000s. At the 2000 24 Hours of Le Mans the team finished third in class with a Porsche 911 GT3-R. The team's most significant result came at the 2001 24 Hours of Le Mans, where car number 83 driven by Fabio Babini, Luca Drudi, and Gabrio Rosa won the LMGT class outright, finishing sixth overall after completing 283 laps. A second Seikel car ran that year in the same race but did not finish. Subsequent Le Mans appearances in 2002, 2003, and 2004 produced mixed results; the 2006 entry, run in collaboration with Farnbacher Racing, finished 16th overall and second in GT2 class.
With the creation of the Le Mans Endurance Series in 2004, Seikel entered that championship alongside continued Le Mans appearances, running Porsche 911 GT3-RS machinery in GT class.
Peter Seikel decided to retire from motorsport at the end of 2006. In 2007, having received an automatic invitation to the 24 Hours of Le Mans based on the previous year's result, the team entered one final race. Seikel reached an agreement with Team Felbermayr-Proton whose drivers — Horst Felbermayr and Horst Felbermayr Jr., joined by Philip Collin — handled driving duties while Seikel's personnel prepared the Porsche 997 GT3-RSR. The car retired from the race after 68 laps, ending Seikel Motorsport's competition history.
Peter Seikel separately operated an off-road 4x4 company and rally team under the name Auto Seikel.