IS250 Questions

[Turbo Lag]

Hi all, I'm in the market to purchase an IS250 GSE20 (preferably a Sports Luxury w/ Sunroof). 

I have a few questions before I do pull the trigger; 

How upgradeable is the standard GPS unit in terms of potentially adding Android Auto/Carplay etc, in other words a standard double DIN headunit with GPS? I assume the standard GPS is outdated and probably quite slow? From the few cars I've seen, I've not come across any that have a different headunit installed. Ideally I store all my audio files on a hard drive/flash drive, and have bluetooth functionality. 

Since I'm quite new to all the different models available, and seeing as ad listings are all over the place, is there any way to actually tell what model the car is by looking at VIN or some sort of model code? Are there any fundamental differences to look out for? Plenty of cars listed as Sports Luxury with the smaller wheels, no sunroof etc. 

How bad of an issue is the carbon build up? Is this something that can be 'helped' by simply getting the engine pretty hot? I come from the land of Subarus where my cars are almost perfectly free of this issue as I simply drive them very hard, which seems to prevent this. Are there any noticeable, physical/visual signs of this? I've read that a sluggish revving engine, or an inconsistent idle could be a few symptoms of this. Is this also something that I should budget in as preventative maintenance if work needs to be carried out? 

How easy is self maintenance on these cars? I'm used to doing most minor servicing myself (ie. fluid flushes) and would like to save on service costs if I can help it. Parts availability doesn't appear to be an issue? 

Any other IS250 oddities to be aware of? I have noticed a few other small issues such as sticky trim pieces, and easily scratched trim but this is pretty easy to identify. 

Thank you for reading! 

[IS250-2007]

Hi Leo,

For the carbon buildup question - mine was running rough and had a mechanical knocking noise when it started cold. When I took it for a service at Lexus Sutherland it cost ¬$120 for them to do a carbon clean. It ran amazingly smoothly after that, a really big difference.

Thanks,

Steve