new car dvd player wont play bloody dvd-r's

its a kenwood kvt-911dvd... much to my dismay when loading the disc it goes error or something, welp it was a compusa disc, which plays fine in my playstation 2. i've heard playstation 2's are the absolute dvd-r test or i've got the impression, anyway... i'm gonna try a different brand, something more expensive.. anybody know if the reflectivity of dvd-r's have something to do with it? would trying other brands be futile? i've heard that dvd+rw's kick dvd-r's compatibility in the ass, would that be a worthwile venture? i could take my dvd-r collection and only have maybe 10 dvd+rw's in my car and like rotate the contents every so often... thanks for listening any input is greatly appreciated

i was under the impression that DVD+R/W didnt play in ps2/standalone players?

bloody ell, oh well i guess no dvd backups for my car. mebbe i'll mount a apex under the passenger dash or something. thanx