He said he encouraged Mercedes chief Niki Lauda to sign Hamilton, believing that Hamilton in a McLaren would be more of a threat than in a Mercedes. Horner explained: "Niki Lauda was at Mercedes and was very keen to take Lewis and I remember encouraging him to take him. However, Horner was quick to dismiss the idea, saying: "We have had several conversations over the years about Lewis joining. Hamilton's career spans nearly 20 years in F1, having driven for McLaren, Mercedes, and Ferrari. Despite his reported interest in joining Red Bull, he has spent his career racing against them as a chief rival.