OT: Laptop cases/backpacks for 18.4" laptop

[Kenneth Brody]

Does anyone on this list have experience getting a carrying case or backpack 
for an 18.4" laptop?  I can't seem to find anything larger than for a 17" 
laptop.

It's a Toshiba Satellite, P505 series.  According to Toshiba, the laptop is 
17.4"W x 11.6"D x 1.68"H.

     http://laptops.toshiba.com/laptops/satellite/P500

Also according to Toshiba, the Targus TXL617 backpack is for laptops "18.4 
inch and under":

 
http://www.toshibadirect.com/td/b2c/adet.to?poid=268655&tab=features&top=true

However, according to Amazon, the inside dimensions only accommodate a 17" 
laptop, up to 16.5" wide:

     http://www.amazon.com/Targus-TXL617-17-Notebook-Backpack/dp/B0001EMM10

(Which makes sense, given the terminal "17" in the model number.  I can't 
find a model ending in "18" or "19".)

Searches for "18 inch laptop case" come up with cases that are 18" in the 
exterior, but still too small inside.  :-(

Ideas, tips, pointers, etc. greatly appreciated.

Thanks.

-- 
Kenneth Brody