Amex backdating without payment history

[Vagabond007]

background : I opened my first credit card in 2007 (Visa with BoA) and was AU on one of the Amex card. I closed both the cards in 2009 as was I went out of country for few years. now I am back in US since late last year.. 

since I came back in US, I opened BoA card (secured 99/500), Amex costco card in Dec 12 and Discover IT in Apr 13. 

My Amex card is backdated to 2007 which lifts my AAoA to 2+ years. When I pulled Experian report, it shows Amex card with date opened 12/2007 but reporting since 1/2013. Also in payment history, I see Ok since 1/2013. I am planning to take my first auto loan in next 2 months. My TU FICO was 735 in April (received with Discover IT card) and salary is close to 115k yearly with no debt at all. 

Question : Considering my thin credit history file, I was thinking of applying for another Amex card which will lift my AAoA further so that I get better rates for auto loan.. but my concern is that my AAoA will go up with new amex card but payment history will still not be very old.. will lenders look at this and ignore AAoA because it has been artificially high due to backdating of amex card? Do you think applying for another Amex card will help at all? 

Thanks in advance.. 

[Capya]

Well....  It seems that adding another AmEx will  1)  Increase your # of cards to 4, which is better than 3 for your score.   2)  Increase your AAoA to ~3 years   3)  Add a fresh inquiry to your report.

Overall with your thin file, I would have to guess that adding another 6 year old CC would raise your credit score even taking into account the new inquiry.

If you only have the 4 inquiries, that's not ideal, but it's far from excluding you from getting a loan.

With your income and your score in the 700+ range,  I don't think an auto loan will be overly challenging.

Unfortunately   I have no idea if the financing people will see the short payment history on your amex and be able to interpret that as backdating a new card.  I've wondered the same myself.   I've always thought that if I was asked about it, I would say that I recently did a product change with amex, triggering the inquiry and resetting the payment history.