Need help and advice

I preordered a physical copy of horizon 4 ultimate edition steelbook from Amazon. I was guaranteed I would have the game today September 28th 2018 but did not receive my order. I couldn’t resist playing so I purchased the digital ultimate edition of horizon 4 from the xbox live marketplace. My question is what advice do you guys have for me for when I receive the physical copy of the game. Should I install the disc on my xbox or just put it aside for my collection. I know Amazon offered a bonus preorder car with the purchase of the ultimate physical copy. Would I still be able to obtain the Amazon preorder car even though I went ahead and downloaded the ultimate edition from the xbox live marketplace. Any advice on my situation would be greatly appreciated.

be totally pointless installing the disc if you already have the digital version
the so called bonus preorder car should be a code sent to you
there is nothing on the disc different from digital