The notion of a fee amount of a new car is wildly implausible. The current block subsidy is 6.25 BTC, about 200k at recent prices where mining was clearly funct

The notion of a fee amount of a new car is wildly implausible. The current block subsidy is 6.25 BTC, about 200k at recent prices where mining was clearly functional. A block can fit around 2000 transactions. Your scenario of a run where blocks are full and fees are the value of a new car (call that $10000) would imply a total miner reward of 20 million, about 100x the block reward that is currently enough to attract minors. In such a scenario if 100x the reward for minors, mining would be wildly profitable.