Well, here's some interesting tid bits about the games:

1. The Broderbund and Mindscape replays are the same.  I know, you're going to call me a liar.  Well, the replay files are the same, the games play them back differently.  If you have both games, you might notice some slight differences:

a) Mindscape: You can accellerate/brake in the air. Broderbund does not do this. So, when Mindscape replays the .rpl file with the driver slowing down in the air, it will slow the car down. Broderbund recognizes it's in the air, and won't slow down. This throws the overall timing factor off between the two games.

b) Broderbund: You have to turn for corners longer than in Mindscape. Check the replay files. Start at byte 0722 (hex) in the replay file. Hexidecimal 08 is a left, 04 is a right, 01 is accellerate, 02 is brake, 00 is null, 10 is shift up, 20 is shift down. Now, you can add these numbers together. For example, brake and right turn is 04+02=06. Accellerate and left is 08+01=09. Now, when you replay a mindscape run on broderbund, take a hex editor and just prior to a corner increase the # of turn values in the file. I'm not sure of the ratio, but the one I was messing with I modified the file for 4 extra turns and brake (mindscape was in air) prior to turn and ended up pretty close to making an identical corner.

c) There are other differences, including being able to pass through different shapes depending on which game you're using.

2. The finish times can be calculated from a replay file. Now this does not take into account penalties.

a) Take the # of bytes in the replay. Subtract 1802 (track size, it's stored in here you know) and subtract an additional 24 bytes (Car and options {manual, color, etc}). Now, divide this number by 1200 (you know 5/100 of a second = 20 ticks, so for every minute you get 20*60 seconds=1200 ticks). This will give you the number of minutes. Now, take the # of bytes-1826 and subtract the number of minutes * 1200. With this number, divide it by 60 and you will have the # of seconds the replay took. Here's an example:

valhalla.rpl is 5700 bytes long.

# of 5/100 ticks=5700-1802-24
# of 5/100 ticks=3874 ticks

# of minutes=3874/1200
# of minutes=3

# of seconds=( 3874 - (# of minutes*1200)) / 1200 * 60
# of seconds=( 3874 - (3*1200)) / 1200 * 60
# of seconds=(3874 - 3600) / 1200 * 60
# of seconds=274 / 1200 * 60
# of seconds=13.70

Now, the only other thing to remember is that the replay is record for EXACTLY 1 second after crossing the finish line, so the resulting # of seconds would be 12.70, giving you a finish time of 3:12.70 seconds. Now this does not take into account penalties.
Now, here is the mindscape (& broderbund version (not as quick though)) replay this example was based on.

Well, that's it for now. Hope we have enlightened your day.