I'd want to know where the oil leak is from, some leaks are easy to deal with, some need major work (like my friends Mercedes at £3,000!) It seems almost every car I check has a suspension arm pin or bush mentioned as an advisory so not a big issue. I've found that unless it's a main dealer offering the warranty they're hardly worth the paper they're written on. I had one with my GS, all glossy and nice in the advertising but a non starter making a claim