Thank You very much Sawys for having shared that ChaseHQ inp of yours, very strange things happen there indeed.
It appears that the last hit you give to 1st opponent is counted 24 times instead of 1, and it shouldn't even be the last hit, since the damage bar is not completed yet.
In that moment it's showed 10K bonus, but score increases by 100K steps 24 times. Very strange thing. And second car is destroyed with 4 hit-bars missing, and hitting nothing
It seems to me no wrong things happen with enemies 3-4-5.
As You say it really seems a casual error, but having an input file we can see if it's reproducible. Gamest's 30Mil are far, anyway
Very intresting the link submitted by Vertex Dan too, it appears to exist some obscure combinations (like Bubble Bobble's PowerUp) to boost some aspects of the game.
Not succeeded in applying them yet, but working on that
Thanks to both of You guys