I've reviewed your smart contract and found a few areas for optimization.

• The variable s_recentBlownTyre should be marked as constant to improve code readability and ensure its value cannot be changed.
• The variable Race.s_recentBlownTyre was found to be unused in the contract. Consider removing it to reduce code complexity and improve performance.
• I recommend following naming conventions for variables as outlined in the Solidity style guide, found here: https://docs.soliditylang.org/en/v0.4.25/style-guide.html#local-and-state-variable-names.

I've identified a potential security vulnerability in the contract related to reentrancy attacks. Upon further investigation, I've found that the fulfillRandomWords and performUpkeep functions are both vulnerable to reentrancy attacks.

To mitigate this risk, I suggest adding the ReentrancyGuard from the Openzeppelin library to both the fulfillRandomWords and performUpkeep functions.