David
Go download the db from the Vehicle Maintenance video.
That is a good place to start.
Watch that video if you have not already.

I'll work up something to show you but it will have to be after work more than likely.  I don't know how busy my day is going to be.

Hi David
Take a look at a site Rockauto.com. It is a good example. You enter info on the Year. make, model until you get to the correct parts which may be supplied by different vendors at different prices.

HTH
John

David - I'm so sorry this took a bit to get back to you.  Work has had me running crazy.

Here below are several pictures of one way to accomplish what you are trying to do.
One thing to note.  I highly recommend that you put your parts into a different table.  The reason for that is you don't have to retype a bunch.  I also don't recommend tying the part to the VIN.
For instance, lets say I have a company and my fleet of trucks consists of Ford F-150s.
If you tie the parts to the VIN you will have to add the same parts in for each truck I own.  May be one - maybe 10 or even 50.  You wouldn't want the data repeated 50 times. That is what you would have to do right now. Because each truck has it's own VIN.

The better way would be to look up the part by the make and model.

Another consideration:  Say I come in and need my truck serviced.  I'm not going to say I need my 4859 serviced.
I'm going to tell you I need my Ford F-150 serviced.  (I have no idea what the last 4 of my VIN is).

You are going to look me up by my name or phone then from there you will see the vehicles I own.

The video above is a good one but even better is the Invoicing video.
That shows you how I made the tables for this example.  If you want a Product Table where you can pick from a list. Watch the extended cut.

With regard to repeating the VIN that is where you would want to use Indexing.
The record it's self is related by the Autonumber.  See the Relationships video if you don't have a good grasp on that.

Hope this helps!