Japan Tourism Automobile and Cruise Association also held an exhibition to introduce and promote new products of tourism automobile. Not only has it offered the tourism automobile manufacturers a smart opportunity to show and promote their new products, but also did it offer a communication platform for the enterprises of travelling-by-automobile service and the manufacturers of tourism automobile.
Improve it please
Teachers: We supply a list of EFL job vacancies
Here's a running commentary for you. Hope it helps.

So far, so good, except I don't know what you mean by "Tourism Automobile".

Now it goes a bit pear-shaped:

Now you're back on track (Good use of inversion after "not only"!):

Then that strange expression "tourism automobile" again:

"smart" doesn't go with "opportunity", but the rest looks good.
Did you mean "an excellent opportunity"?

Word order problems. "it also offered" is better.

This part is fine grammatically, but I'm not sure what a communication platform is. "a venue for the exchange of ideas/information"? "a forum"?

And the ending collapses into near unintelligibility.
"car rental enterprises"?

Finishing with that peculiar "tourism automobile" again.
What does that mean?
I'm also puzzled by 'tourism automobile'.

Firstly, 'automobile' is an obsolete word in British english, I do not know if it is used in american. 'Car' is invariably the British word of choice for this.

Do you mean perhaps

'hire car' - vehicles hired by tourists to self-drive during their stay

'tour bus' 'coach' 'minibus' - larger vehicles that would be used to move groups of tourists around.

'taxi tours' 'guided tours'. This makes more sense if you are trying to describe a single car being hired with a guide/driver.
(1)Tourism automobile = travelling vehicle = tour bus
Could not you find out the definition "automobile = vehicle" in your dictionaries?
(2) communication platform = the exhibition served as "a venue for the exchange of ideas/information"

PS. (From American Heritage Dictionary)
Automobile: A self-propelled passenger vehicle that usually has four wheels and an internal-combustion engine, used for land transport.
Students: We have free audio pronunciation exercises.
Hi Jobb,

Let me present one possible re-write:

"Japan Tourism Automobile and Travel Association also held an exhibition to introduce and promote new products for automobile tourism. Not only has this exhibition offered these manufacturers a fine opportunity to present their products, but it has also served as an advertising venue for auto travel services and bus and recreational vehicle manufacturers."

('Japan Tourism' is the name of the government organization which promotes tourism in the country.)
Hi me again,

Yes of course I know what automobile means. The problem is that we were all connecting to the word 'Tourism' as though tourism automobile were a type of vehicle, and that sounded really odd to a native speaker.

I still think that Vehicle is a better word if you want to cover various types of transport, automobile sounds like something from the 1920's to me.

I was only trying to be helpful...