Pretty simple fix! There's a rather infamous pirated copy floating about that decreases the file size for the game by deleting/changing a couple of game files. While the copy normally works 'alright' (as in the player can use the copy to complete the entire campaign), there's been consistent reports of changes being made to the Electaurus vehicle that causes the game to crash when entering it.
I'd highly advise looking around for another copy of the game from other sources, such as the original installation CDs. We sadly can't link directly to any pirated copies of the game just to keep our hands clean and avoid upsetting the current copyright holders of the game. Handing out copies might land us in hot water later down the line, in short! Clean copies should have no issue using the Electaurus.
I should also point out that riding the Electaurus is never mandatory to 100% the game. The player can unlock it from Level 1's Street Races, and then just simply never use it and still obtain all 100% bonuses if the player is aiming for that.