hi mate welcome to bmwoc....hmmmmm if i had that choice i would go for the 335d or the 525d only because i need something quick with good mpg.....the e46 m3 is one of my favourite cars but having 2,nearly 3 kids it just wouldnt be practical
i have heard a few people have tried the wd40 thing and it worked.i would try spraying some onto a cotton bud then cleaning the connections with it.it wont damage it