Re: real racing 3 upgrade stuck in download mode
The process of updating the game was most likely interrupted during the DL...and unfortunately, if it hasn't picked back up by now (2 days later), you're most likely out of luck and will need to reload the game again fresh.
One question though, having played Real Racing 3 myself...are you attempting to update the game via cellular service or over WiFi? I know that game has particularly large updates, usually requiring being connected to a WiFi network to even initialize...my question would be if you started it in a WiFi network, are you trying to also complete it within one as well? It may be waiting to connect to a WiFi network in order to restart again.