Olds Alero VIN Description

[myowneq]

I am wondering what the codes concerning the VIN are. I have found some limited information, but not all of it. Here is what I have. I am curious as to what digits 4-8 stand for.
Thanks

Position Information Decode

1 Region North America
2 Country USA
3 Manufactorer Oldmobile
4-8 Unknown Unknown
9 Check Digit Check Digit
10 Year Man. 2002
11 Assembly Plant Lansing Craft Center, MI
12-17 Serial Number Serial Number

[AleroSS]

perhaps they pertain to what key is used - they can cut you a key simply from reading the vin number...

[Oldsman]

in the VIN it tells you if GX, GL, or GLS. that is one of the 4-8 ones.

[Fast Eddie]

4th digit = platform (n-body)
5th digit = trim level/series
6th digit = body style (# o'doors)
7th digit = restraint system
8th digit = engine