Guys,
while I agree it's 'hours and hours' of fun trying to do the installation yourself, keep in mind that according to DEI, any DEI products, http://www.directed.com/ that have life time warranty will be voided if the installation is not done by a certified shop. therefore i would highly suggest that you use that precious time for a different DIY, save the hassle, and get it installed. it usually is from 180 to 250 based upon the product. and at the end you'r really saving 30 to 50 max on the installation. but voiding the warrranty. is it worth it ? you make the decision. However i would suggest choosing a shop who can show you their records for mercedes specific alarm installation. we dont want newbies messing up the connections either ! a remote start with keyless entry whether diesel or not by viper is usually around 199 with installation. can't beat that i think.
good luck !