I got an 08' E63 which has the K&N typhoon cold air intake already installed, however I've been trying to figure out whether or not those are worth keeping on? I've read some different reviews saying they tend to leak oil into the MAF and that they suck in too much heat from the engine. Does anyone recommend another air intake system that does better with reducing heat intake, or should I stick with the OEM system and just install a filter like BMC? All of the threads I've come across are from years back in like 2013, so I'm wondering if anyone has recommendations as to what they think the best route would be and if any new systems have come out since then that seem to be promising. I've also seen people mention RPI scoops, so wondering about them too. Thanks in advance.