Just because motor week didn't get the time you like doesn't mean they're not credible. It could be weather condition and track condition too you know? Here are some other test made my auto week for you to compare with so it'll be fair, same mag & same track.

2001 330Xi:
0-60 = 6.2sec.
1/4 mile = 14.7sec @ 96 mph
epa mileage = 20/27

1998 323is:
0-60 = 7.3 sec.
1/4 mile = 15.5 sec @ 90 mph

2003 CL-S:
0-60 = 5.9 sec.
1/4 mile = 14.5 sec @ 96 mph
epa mileage = 19/28

2002 NSX:
0-60 = 5.0sec.
1/4 mile = 13.1 sec @ 109 mph
epa = 17/24

2003 G35 sedan:
0-60 = 6.2 sec.
1/4 mile = 14.8 sec @ 95 mph

Those are just some of the tests. Now how can you say their test is not credible when they get those kinds of time for those cars? To analyze their TSX time a little further, if you noticed, the trap speed is @ 90 mph. That just shows that its top end power isn't all that great. So I'm not too surprised w/ the ET of 15.9. If they can't drive, i.e. can't launch, then their trap speed would have been higher. But it seems like they launch it the best they could.