There are no major difference between 97 and 98. The /6 will have the 'sports package": staggered wheels, stiffer suspension and shadowline trim (i.e. flat black around the side windows rather than chrome). My '98 has side airbags whereas I don't believe the '97 has them.
Other than that it will depend on the options that came with the original car: xenon headlights, audiophile stereo, CD changer, phone, etc were all options. I believe all body panels (incl bumpers) are identical.
Don't forget to find the delivery date for the '97. It may be a year older than you think because there was no '96 model year.
... and of course the obvious difference: auto and standard are night and day difference on these cars.
Keep in mind, if the 98 does have shadowline, the bumper and side mouldings will not have chrome in them as do all '97 sports- even the 6 speeds. Same for the trim around the windows.
At one time or another before 2000, they changed the side view mirrors from '97 or '98- they got smaller. The gas cap changed as well. I am also pretty sure that rain sensing wipers showed up in '98's- not an option on '97's. (Unless you're just silly like Tyrone.)
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