JPTL

My GT has a build date of 9/28 (1990).
I wouldn't want any other date than 928 (plus it was a Friday). That's Mojo.
Wonder if the guys finishing my car up on 9/28 in 1990 gave the date any significance, or were simply getting ready for the weekend.

Vilhuer

Those numbers are probably for calendar year 1988. Correct model year production numbers should be:

There is question mark over 928 S4/SE ROW if its correct or not. Actual last VIN could be higher or there can be gap(s) if S4 and SE have different VIN sets. Any number can be wrong but some new evidence is needed for that.

Model year started usually in late June or early August on previous calendar year and went to June of the actual VIN year. There are several exceptions to this rule.

'78 MY production started around same time as 928 was introduced in March '77. Its still unclear when US model series production started. It was either several months later or number of cars made in early months were really small. When US VIN 0054 was made some time in summer '77 factory was already making ROW VIN 0753 and Japanise VIN 9522 at same time. Japanise VIN started from 9501 for that MY.

One source says '83 MY production started month or two later than normally.

'92 ROW GTS and early '93 US GTS production started around 6 months late. It seems there were several months long stop in 928 production in later part of '91 calendar year to clear old S4 and GT stock from dealers. ROW production started again in late '91 and US in early '92 calendar year.

First '94 MY US cars were done very early in '93 calendar year. This also means '93 MY US production stopped some 6-7 months before normal.

It was all mixed on same single one production line. ROW, US/Canada, US/Canada, ROW, ROW, US/Canada, Japan, US/Canada, US/Canada etc. Result from this is that there are from 2 to 5 or 6 different VIN sequences for given model year. See other thread for more details:
https://rennlist.com/forums/928-forum/394457-master-vin-thread.html
All those different sequences were running side by side. If US production was larger for that particular year there were more US models on the line on average and less ROW cars. '88 MY has largest number of separate sequences. 5 at least and possibly 6 in case UK SE has its own separate set from ROW S4's. Cars belonging to these different sets were all build in one single production line all mixed up in order which they were deemed best to be build because of several sometimes conflicting reasons.

One very important reason for specific build order is paint color. Its always pain for paint line to change color between bodies in car factory. Since 928, 911/964 and starting from middle of '91 MY also 944 and later 968 and 993 were all painted in same paint line cars were grouped together to form as long as possible sets of single color. This means if there were some rare color ordered for 928 its possible such cars production start was put on hold for a while to wait few same color orders for other models. These cars could then all be painted with one color change on the line. Only nowdays can specialized small car factories (like Valmet automotive in Uusikaupunki Finland which makes Boxsters and Caymans for Porsche) change color easily for each individual body.

There were possibly other production methods related reasons too why some cars might have been done more quickly than others. Selected equpment also could mean longer wait. No sunroof in later MY's is good example. Its possible these bodies were made in batches instead of individual bodies and this can be reason for longer delivery time they seem to have had.

In some cases there can have been pauses for some market production because of lack of orders or shortage of market specific parts. If for example US side marker lights or gearboxes with ROW ring and pinion ratio were on short supply only ROW or US cars could have been made for a while. Its possible also some market specific parts like those only used in RHD models stopped production to those markets when they were not available for some reason.

Whitesands

My vin No is 1026