2-doored car or?

[atabitaraf]

I don't know where to use the first part of a compound noun, with -ed or without it.
two-doored car/two door car
three-wheeled motorcycle/three-wheel motorcycle
three way extension/three wayed extension
five sided shape/five side shape
etc.
I'm looking to find the rule.
Thanks,

[5jj]

There is no rule.

[atabitaraf]

There is no rule.

Which of the mentioned examples are correct? Are the others not-usual or incorrect?

[5jj]

In my opinion (and that's all it is) we speak of:

a two-door car
a three-wheeled motorcycle or a three-wheel motorcycle
a three-way extension
a five-sided shape.

Sorry, but I can offer no explanation. Let's hope others can.

[Barb_D]

In my opinion (and that's all it is) we speak of:

a two-door car
a three-wheeled motorcycle or a three-wheel motorcycle
a three-way extension
a five-sided shape.

Sorry, but I can offer no explanation. Let's hope others can.

Same for all four for me, but I can't say why a "2-door car" and a "3-wheeled bike" sound "right."

[5jj]

Same for all four for me, but I can't say why a "2-door car" and a "3-wheeled bike" sound "right."

I wish I could.

[atabitaraf]

Thanks a million.
Even when you say there is no rule or I don't know it has a great meaning to us. It means in this case I have to refer to 'Google' or to your culture and not to grammar or logical rules.

[Raymott]

Thanks a million.
Even when you say there is no rule or I don't know it has a great meaning to us. It means in this case I have to refer to 'Google' or to your culture and not to grammar or logical rules.

No, please don't perpetuate "having to refer to Google". This would not solve your problem at all. Google is ruthless in cataloguing crap as well as it catalogues proper English - unless you mean referring intelligently to trusted sites on the web with the help of Google.