To my knowledge, there are currently 3 reputable companies offering warranties for cars without warranties:1) Wheelguard - highest premium cost, uses new original parts, fast claim process2) Opal - medium premium cost, uses new parts/rebuild parts/recon parts (depending on case), medium claim process (case dependant)3) Autogouard - lowest premium cost, doesn't cover all major parts, others similar to Opalyes it does gives a peace of mind..to me that matters most as you can rempit the car as much as you want, hoping that something will breakdown along the way n can claim from the insurance company..some of our 335i members claimed almost rm10k during their term with Opal..common things that were claimed are ABS pump issues, HPFP, injectors, boost solenoids, vanos solenoids..most worth it if u can claim a pair of new turbos..hehe..another disadvantage is some prefer to service our cars at our own specialist workshop, by having to service at only authorized panel workshops, it's hard to find the right workshop with that level of knowledge on our cars..another issue would be if any mods done, this will void the warranty unless u can kawtim with the workshop and/or remove the mods before making any claims..by the way which z4 are you getting? z4 35is? for a 2009 model it is quite new (also depends on the mileage) there might not be any problem for the first year of ownership..the number of claims made all depends how the previous owner used it, how hard u push your car n of course luck
this car warranty insurance was also previously discussed in detail here:
http://www.bmwclubmalaysia.com/newforums/index.php?/topic/26134-car-warranty-insurance/