I need some help in correctly setting up my tables. I've never had these kinds of requirements before so here it goes.

Let's say I need to setup a system to store different characteristics of an automobile. Let assume I want to store info. on all possible combinations of TYPE (car, van, truck), COLOR (blue, black, etc.), TRANSMISSION (auto, 5-speed, etc.) and DOORS (4-door, 2-door, etc.).

The way I originally though is to create 3 tables as follows:

TABLE: CLASS
CLASSID   N-1O Primary key
CLASS     C-10

This table will hold one record for each type of characteristic (TYPE, COLOR, TRANSMITTION, DOORS.

TABLE: CODES
CODEID   N-10 Primary key
CLASSID  N-10 Foreigh key
CODE     C-3  (Code assigned to characteristic - e.g. A)
DESCR    C-20 (Description of code - e.g. VAN)

This table will hold one record for each "CLASS" and characteristic.

TABLE: COMBINED
COMBID     N-10 PK
COMBCODE   C-10   (Combined code of each different classes)
DESCRIPT   MEMO   (Combined description of different classes)
COST       N-10-2 (Cost of each particular kind of car)

This table will hold one record for combination of each "class" and characteric.  

Example: COMBCODE  DESCRIPT                     PRICE
         A1A1      Car, Blue, Auto, 4-door      $10,000
         A1A2      Car, Blue, Auto, 2-door      $9,500
         A1B1      Car, Blue, 5-speed, 4-door   $9,750
         A1B2      Car, Blue, 5-speed, 2-door   $9,250

Now, I need to "update" the COMBINED table data everytime a user changes (add,delete,edit) codes in the CODES table. How can I set this up so that I can easily do this? Relationally speaking, is my table setup adequate to handle this (I don't think so)?