For the SRT6 expect to spend about $200 in time and money replacing the intercooler pump. Easy job if you have jack stands or a lift, parts cost about ~$130 and plenty of guides online.

Apparently a number of us have issues with the RCM failing. With a decent pair of gonads and a soldering iron that's an easy fix as well. Both of these can be knocked out in a Saturday.

Those are the only two serious issues I've seen on these cars (owned both an SRT6 and Base, both coupes). Next to that it's just shitty electronics and plastics, typical for Benz/Chrysler.

Do be aware (and sounds like you probably are) that mechanics and dealers will take you to the cleaners on parts cost for these things. Read the forum and shop for parts yourself and these really aren't too expensive to maintain. Don't ever let the dealer buy parts for you! Bring your own and pay for labor. Everything else is covered on the Sticky archive.

Once you knock those two big things out, they're awesome machines! Search around for "Throttle Reset" and "Seat belt chime disable" to make your life even better once you buy.

*Edit: Final thought, if you can, get the dealer to put some decent rear summer tires on as they're a bit pricey and you don't want to pay for if you don't have to! Traction will be the limiting factor on these and you don't want to be running on Chinese all-season rubber.

Enjoy the ride!