Complex sentence: The Tagora was ultimately launched under the Talbot brand, which was relatively unestablished in the marketplace and had a questionable pedigree, which was an unfavorable trait in the executive car market ruled by established names like the Ford Granada.
Split into simpler sentences: The Tagora was ultimately launched under the Talbot brand, which was relatively unestablished in the marketplace and had a questionable pedigree. The executive car class was ruled by established names like the Ford Granada.