Better notification in Safari when a download starts?
You could create a folder action in Automator, to watch for new files in your Downloads folder and display a notification banner whenever it detects a new file.


Open Automator and create a new Folder Action
Next to Folder Action receives files and folders added to choose your Downloads folder   
Search for 'notif' and drag and drop the Display Notification to the right
Enter your own text and save


It should look something like this:




It's not the ideal solution, but at least you'll notice something has started downloading. Hope this helps.