Complex sentence: The Reliant Rebel was a small car produced by Reliant between 1964 and 1974, conceived as a niche rival to the Austin Mini and Hillman Imp, it was seen as the smart alternative as it had a rust free body, robust chassis and frugal fuel economy.
Split into simpler sentences: The Reliant Rebel was a small car produced by Reliant between 1964 and 1974, conceived as a niche rival to the Austin Mini and Hillman Imp. It was marketed as the smart alternative, because it had a rust-free body, a robust chassis and frugal fuel economy.