I'm the original owner of my car (Inferno Red 2009 Challenger RT) and I've done a lot of things to it - a few that I regret. Performance mods include an 85mm throttle body, Moroso catch can, Aria CAI (same as the Legmaker LC Hammer Design), used SRT headers, Corsa catbacks (the original set), BC Racing coilovers, Diablosport Predator Tuner and a dynotune. In my opinion everything I listed is a necessary mod if you want to get the most out of your car (other than the coilovers - you do need some sort of good suspension system and the 2009 Challenger just didn't have it). Some will debate the 85mm TB vs the stock 80mm - meh, you're choice. Just don't go bigger than 85mm unless you're supercharging. The catch can is also debatable but EVERYONE I know who knows these cars recommends one. I went cheap and installed a set of used SRT headers for $150 but the Corso catbacks (installed were about $1,000. The exhaust manifolds on the 5.7 RT are HORRIBLE and the most restrictive - dump them. The used SRT headers bolted right up to the Corsa catbacks. If you're going to add a tune you need a CAI and a tuner - this is what leads to the BIGGEST bang for your buck - the dynotune! Buy a DS tuner and a decent CAI - NONE are better than the other in my opinion. A "canned" tune with a CAI is only going to give you a few extra HP, not much (maybe 5-10). Trust me. Spend $100 and get it DYNOTUNED! You need a CAI and a tuner for dynotunes otherwise you can't return the car to stock if you want (unless you take it back to the dynotuner. A tuner does A LOT of extra things that are invaluable! Buy one from Diablosport, it's the best for Chrysler products (and SRT). All this sounds complicated (it is somewhat) but I figured it out, so can you. The tuner can get you into trouble if you start monkeying around with things and you don't know what you're doing. But they can do some AWESOME things too - they are a must have item. So, with the headers, catbacks, CAI, tuner and dynotune I got 30 rwhp and 60 rwtq extra! That's a lot considering. That equates to about 415 hp and 450 ft/lbs tq. Forget all the crap that a CAI will give you 15-20 HP - they won't. A dynotune with the other items will do it. I will supercharge my car one of these days when I have about $10,000 laying around - that's the BIG increase. You can SAFELY push the 5.7 engine up to about 475 rwhp without modding the engine or forging it. That's around 550 engine hp! (I can't remember exact numbers at the moment). Suspension (because the car sat too high): This has been a nightmare for me. In hindsight, I wish I had just bought some used SRT springs and left it alone. Instead I bought a $2,000 Eibach kit that was really great - but the car was too low FOR ME. Every speed bump, curb, driveway, etc was a thump, crunch or a scrape if I wasn't really careful. So I bought some other springs that said would lift it - they made it even lower (there is no standard amongst spring manufacturers it seems). Then I bought some mid-priced coilovers that wore out after a couple years. The great thing about coilovers is you can make the car as high or low as you want (within the coilover's limits). Now I'm debating going back to standard suspension or buying some high end coilovers like Eibach. If you're going to spend money on mods - don't go cheap! Great coilovers are Eibach and KW (I think KW makes the ones for Mopar). Bling: Everyone wants their car to look nice but this stuff can get costly. It's your money and car - do what you like, just know bling doesn't make the car go faster. I put some nice chrome covers under the hood (radiator cap, oil cap, fuse box cover, etc). I added a chrome T-shifter and the metal pedals. I removed all stripes and added some nice hockey stick "HEMI" decals that really look nice. Then I quit - all future money goes for performance mods - it must make it stronger or faster. Put good tires on your car - DO NOT skimp on tires! Nitto's are great but they're also expensive and soft. Plan on changing them out more often than other tires. I currently have Continental DWS Extreme Contact's on mine and that's all I will buy in the future most likely. 245/45-20 front, 275/45-20 rear. Boss chrome wheels. Gotta run, hope someone finds this of interest.