Creating a macro: If Cell A1 contains x then add x to the end of a string of text.

Hi all,

I'm not confident by title describes my problem very well but what I'm trying to do is the following:

My spreadsheet is used to track cars and every month I add new cars to it. At the moment I can download the details of said cars which I break into separate cells using text to columns.

The car model is displayed as a string of text and the transmission is recorded in a different cell as M(anual) or A(utomatic). What I'd like a macro to do, it check each row to see firstly if the car is an Automatic, if it is, then I'd like it to add the text AUTO to the end of the existing model description. If it's Manual then I'd like it to do nothing.

Also (as if this wasn't tricky enough) in SOME circumstances the model of the car might already have the text AUTO in it. In these cases (if possible) I'd like the macro to skip and not add the text in again.

Hopefully that explains things enough but if not then please ask me anything else which will help.

Many many thanks for any and all help I receive.