His first race in Formula 1 was at the 1970 Spanish Grand Prix with a Lotus 49. Race organisers limited the race to 16 starters, resulting in Soler-Roig failing to qualify, despite lapping only a tenth of a second slower than Mario Andretti. However, on race morning there was a suggestion that the non-qualifiers might be allowed to start after all, so their cars were placed on the grid, only for the organisers to stick to their original decision, removing Soler-Roig's car from the grid as well as those of Jo Siffert and Andrea de Adamich. He subsequently participated at the Belgian Grand Prix, driving the Lotus 72 that was meant for Jochen Rindt. However, the car was not ready for Friday's practice and he only managed to complete three laps in Saturday's qualifying, and was therefore not allowed to start the race. His final Formula One outing for the season was another non-qualification at the French Grand Prix in a 49. He won the Spanish GT-Sport Championship that same year.