you are in UK..... when I search for ship wheel here in the US, I get 54,000 returns......so I'm not sure why that wide of difference unless you are searching only UK or have some other filters on.
If searching in the US, search will filter out sellers who don't ship to the UK......assuming you are signed in.
If your question is primarily about searching in the UK, you should ask for help on their boards as they will be more familiar with use of filters there. I would also give a concrete example of exactly what your search terms are, as that will help others try to replicate your search and find out answers.
