Is it in the factory you visited last week that this kind of

分析理解句子,就是把所有的修饰语都去掉,意思是完整的.你还没有加疑问号,说明平时学习不太关心此类问题.
你这句话,有些问题.个人理解,是Chinglish.
我们来看看这句话：
Is it the factory （you visited last week） that this kind of car is made （by/in）?
这样就明确了,重点是那个工厂.
这种车是你上周访问的那个工厂生产的吗?（没有突出车）
是你上周访问的这个工厂生产了这种车吗?
是这个工厂（你上周访问了,并且生产了这种车）吗?
主语是 IT
谓语结构是 IS the factory
you visited last week 和this kind of car is made 都是修饰 the factory的.

先声明，下面是我个人的意见。
这是一个强调句转化的疑问句。
首先请看一般的陈述句：
This kind of car is made in the factory (that) you visited last week.
（这种车是由你上周参观的那家工厂生产的）
主语car,谓语部分是be made ,you visited last week是一个定语从...

这句句子是一句强调型主句加一句定语从句：
强调型主句：Is it in the factory that this kind of car is made?
改成陈述句： It is in the factory that this kind of car is made.
改成非强调句子： This kind of car is made in the factory.

这句是强调句的一般疑问句，
强调句的正常语序是，
It is in the factory you visited last week that this kind of car is made
找出句子的主干为，This kind of car is made in the factory.强调地点状语in the factory，
该句的形式主语是it，...