I try to explain some things to our foreign visitors:

There are four important documents to drive/ own a car.

1. The driving license- In Germany you have to be 18 yr. old to drive a car.
2. The KFZ- Brief.This document tell other people that you´re the owner of the car.
     This is pg.2 of the "Brief"
 
The KFZ Brief has 6 sites. On page 2 are some numbers I will explain:

#3 is the type of a car-e.g.Corolla, Celica, Crown- this one is a Celica TA40 
#4 is the VIN
#6 is the top speed
#7 is the power of the engine in KW/ rpm- Here it is 80/6200 that means 109PS.
#8 is the engine volume in ccm not in cui :-)
#13 are the Datas for the lenght(4330mm) the width(1640mm) and the height(1325mm)
#14 is the weight of the car in kg(1030)
#20-#23 are the tyres you can use on this car
#30 is the noise whith engine on
#31 is the noise while driving

You should keep the "Brief" at a safe place at home and don´t drive with it in your car.The person who has the "Brief" is the owner !!!!!!

3. The third important thing is the "KFZ-Schein".This is a little copy of the "Brief"and you have to show it to the police when they caught you after a little race:-)).You have to put it with you (like your driving licence).

4. The last imprtant document is the AU or the ASU certificate.If your car is built before 1968 you don´t need it.
If your car is built between 1968 and 1991 and your car has no catalytic conv. you have to pass the ASU every year.
If your car is equiped with a cat. you have to pass the AU. The AU is valid for two years.
After passing the ASU or AU you get a certificate.You have to put it with you.

OK, these have been general facts for normal people driving.

Customizing your Toyota is not quite easy in Germany. There´s a very big aftermarket industry, but only if you own an Volkswagen, Opel, Mercedes, BMW.....

The older your Toyota the more problems you will get by looking for parts. For Models from 1990 and on it is not as difficult, but if there are 50 manufac. for e.g. lowering suspension on Volkswagen Golf, there is only one manufac.for your Toyota.

Example to lower your Corolla AE86 in Germany:

If you found the needed part, you have to install it or have it done in a garage.

After installing you have to drive to your local TÜV Station immediatly (same day)
because you are now driving w/o insurance (don´t forget #13- height in the KFZ-Brief has changed 1325mm -40mm)

Show the TÜV engineer the documents that have been sent with the springs.

If no documents are available, there´s no cheap way to pass the TÜV!!!!! 
Ask the manufac. before ordering the parts!!!

Ok, you have the documents.The engineer will know look at the install hints.
There are often different hints like: roll or cut the fender (to avoid scratching tyres), axle adjustments, or only with the stock rims/tyres,only stock steering wheel or some more wicked things.
If it all is alright he will change the data in your "Brief" ,#13 is then: 1285mm. 
The fee for this is about 90,00 DM.(10min)

Now you have to get a new "KFZ-Schein" (the little copy of the "Brief") so you drive to the civil servant and ask for a change of "KFZ-Schein".After getting the new one you pay the next fee(15,00 DM)

This is the procedure with every part you want to install on your car: alloy wheels, tyres, steering wheels, exhaust systems, suspension, roll-cages.....

Ok, all parts together is possible, but who can afford buying those things in one time???

Below you will find some parts that you can get in Germany: