after a lot of reading on the Sprinter-Source Forum I settled on this ODB scan tool
so there is a $9 mail-in rebate - but they really make you work for it
Here are all the forms you have to fill out and send in to get the lousy $9 rebate. For me the more difficult the vendor make the rebate submission the more I am determine to not let them get away from paying it. Yes, they designed in many potential disqualifying steps to increase the chance of your submission would be disqualified.
the scangauge is the larger and more legible display; i chose to buy the windshield mount because the 3 buttons are located on the back side
at the mean time i am binge-watching cooking shows
a diagnostic tool for Brunnhilde (an Auto Enginuity) just awhile back so why buy this one?
The Auto Enginuity diagnostic tool is for servicing the vehicle. It is diagnostic while this one is a multi-function gauge while driving. This gauge cannot display many propriety diagnostic trouble code of the T1N Sprinter. Alternately the Auto Enginuity's diagnostic tool requires a PC to operate so it is not suitable for use while driving.
Update - 19:00 PST
Reading through the 60 page user manual and the contents of the website I am very impressed how well all the documentations are written. The manual is very clear and concise. It is by far one of the best product technical documents I have read recently.
the user manual is very concise
a partial list of available gauges for 2005 t1n sprinter - i do not have high expectation of some being terribly accurate (e.g. instantaneous MPG, or short trip statistics etc)