You can install our site as a web app on your iOS device by utilizing the Add to Home Screen feature in Safari. Please see this thread for more details on this.
Note: This feature may not be available in some browsers.
Because I know this is a common issue...
I can confirm that a Lyon & Healy Style 23 concert grand harp with a travel cover will fit in the back of a Model Y. The driver's seat will not go all the way back but otherwise it fit quite well.