Finding what you want

How many times do you know what you want but can't find it easily online? People look for items online by specification (e.g. a microwave that mounts under the cabinet and is a certain dimension. You want to find a replacement part or you are looking for a particular item. You know the model number. You know the manufacturer but it takes a really long time to find it via Google. The information is available online at various web sites but it is not aggregated at a single site. This makes finding the products you are looking for difficult. There has to be a better way to find what you want. Search tools should provide a search by attribute, drill down by classification, and comprehensive results. You should not have to become the search engine, piecing together information from many different sources.