I am in N Austin and also have a RAM in addition to an Alfa. My ram has a lifetime warranty (both powertrain and "bumper to bumper" with many exclusions). I have used Mac Haik G'town I-35, Maxwell on 620 and Covert on 183. I will not let Covert touch another car I own, If you're really curious about why, PM me. Both Maxwell and Mac Haik said they won't work on these cars. I have a QV, but not sure that's really an important point (although QV oil change if you use the siphon technique is really easy, no need to even raise the car). But I suspect that could change depending on who you talk to. Maxwell is so booked out that you can't even get a timeslot on a car like a RAM for weeks... so it's unlikely they're eager to take on a science project. Mac Haik was less busy but also said they won't service them (but again this could possibly change).
Nyle Maxwell Alfa, when it was still there, made two mistakes on the one and only 1 oil change I let the dealer do (as it was complimentary): 1. they over-tightened the drain plug and rounded it off (and a fun note on that: I have bought 2 replacements and none fit!!!) and "lost" 4 of the pan screws. Of course, when they take the underpan off, they just throw the screws on the floor and then pick up what they can find easily which is obviously less than all of them, and that's what you get attached to the car... another reason why I insist on doing my own oil changes.