While they don't disappear on death, the chances of you getting the same set of upgrades (or even a half decent set) in the shop after your death are slim.
Also, salvage is reset on death, you only get salvage after death by cashing in crash coins.
Just a quick question on the salvage issue. If you finish a season and go straight into the next one, then Crash gives you some salvage for any coins you may carry over, correct?
But unless I'm mistaken if I decided to start a new run of, say, Season 2, then I would start on zero salvage and not have any coins to give to Crash? Is this correct?
At what point does the game auto save for you? Because wouldn't it be better to take a save at the start of a season after crash has given you some salvage, and then if you happen to die at any point during the season just reload your original save and get your salvage back?