I have been thinking about this Daffy, and this is what I came up with:
You would have a chart of different ages in a country from 18-23, 23-28, 28-33, 33-38 etc. etc. You should then make part of a certain group for a certain percentage, so lets say 18-23 of age, 78% of them in European Country X is into Sporty Hatchbacks in the year 1996. At the same time, the same group of 18-23 has 12% of them interested in Sedans in the same country. So what you get eventually, is spread over different groups, a certain percentage of the population ages interested in this group. This way the targetgroup will count as the interests of the buyers. Of course there can be overlap, as some of the 18-23 sporty hatch buyers, might also like sedan. So the number never needs to add up exactly to 100%.
Ten per country, you could tie the amount of money each group has to spend to the age-groups. This way you could say 18-23 is more attracted to sporty hatches because they are cheap (and of course more power), a small percentage which has more money to spend would like a convertible, a sedan or an SUV for example.
The group of 33-38 would really like a sedan, SUV or station(wagon) because of having a family with kids and going on vacation + also having money to spend.
To give you a better view, heres a chart. It's quite hard to explain in text anyway.
https://dl.dropboxusercontent.com/u/111 ... groups.pdfThis is what it could look like. I didnt finish all the percentages, because it's a hell of a job to get right. Those percentages SHOULD add up to 100%, so its not just random number inserting.
The interest in different cars like sporty hatch and sedan could be overlapping.
Wonder what you think of this
