This is exactly the industry-problem SamacSys are trying to solve with their ECAD content (Symbols / Footprints / 3D Models). They are independent and offer their ECAD Models unlimited for free to Engineers. All the leading EDA formats are supported like KiCAD, Eagle. Their website (ComponentSearchEngine.com) where you can download the content also offers builder tools and a free fast turn around request service, so you can get models for almost every part you want quickly even if its new. SamacSys are distributing their ECAD Models to Findchips.com, Mouser, RS etc and behind all the leading EDA tool companies like Mentor, Zuken etc. Currently over 15,000,000 parts have CAD models. Hopefully this industry challenge is finally solved! - full disclosure i have worked with SamacSys, hence having the knowledge but they are really about fixing this problem for engineers so wanted to comment.