which car is better a 2008 acura rl or 2016 mercedes c300 4matic?

AN AUDI QUATTRO supercharged is the BEST between them ALL! BUT< I would shoot for the BENZ between these two choices! I LIKE the ACURA/HONDA car, but a EUROPEAN CAR is made to last for THIRTY +YEARS and they MOSTLY will NOT RUST! The AUDI is the BEST at body work and PAINT! THE only reason MERCEDES makes a 4 MATIC is to compete with the AUDI QUATTRO CARS with AWD and TURBO CHARGING! LOOK INTO CARS.COM for a god used BENZ SLK hard top CONVERTIBVLE! They are UNDER $10,000 and even LESS!  iF you NEVER owned a REAL EURO CAR< you are in for a TREAT! There are RULES to follow HOWEVER!>>YOU MUST use ONLY genuine EUROPEAN FULL SYNTHETIC OIL named 229.03/229.05 OIL! I PREFER PENNZOIL ULTRA EURO cuz it gives an EXTENDED ENGINE WARRANTY to 500,000 miles! It is MADE from NATURAL GAS and is THE  oil of FERRARI! IT CLEANS al the n[baked in MUCK OUT and protects the CONVERTER and O2 sensor and OTHER sensors from SLUDGY TARRY buildup and premature WEAR! Same for the ENGEIN PARS! NEVER USE VALVOLINE or PRESTONE< only genuine BENZ fluids and at 100,000 mile intervals have ALL FLUIDS CHANGED even the BRAKE FLUID using ONLY PENTOSIN  Use BLAUPARTS for any part needs to save BIG MONEY on parts, or 1-800-ALL-EURO in MICHIGAN! In REALITY all cars are LIKE THIS! The ACURA wil PROBALY use a TIMING BELT that wil cost about $500 to change1 The BENZ will NOT have on, but only TIMING CHAINS that can last the LIFE of the car or at least 200,000 miles! BUT AGAIN the OIL CHICES for each are CRUCIAL and NO PRESTONE or VALVOLINE may be used in ANY of them or EITHER of them! I EVEN prefer the SMELL of the BENZ car! ACURA smells a bit like FISH inside ONPURPOSE!  Check out used AUDI CARS at CARS.COM! Or USED BMW xDrives! They are BOTH GENUINE AUTOMOBILES and NOT just CARS!  I bought me LAST BENZ from CARGURUS adn it was ONLY $3400! It was FANTASTIC getting 32 MPG all day long ( after I tuned and cleaned it) the FINISH was PERFECT< and it drove TOTALLY PRECISELY in ALL types of weather! VERY TIGHT suspension that LOVES curves FUN with BOSE inside and a GREAT factory RADIO! I hlkped someone get a good used BMW STATION WAGON at an AUCTION for about $3200 as well! I told the NEW owner to expect paying ONE K more as the TIRES and BRAKE PADS were shot and it needs ALL NEW FLUIDS! She is as HAPPY as can BE with it! The FINISH was STILL PERFECT and had FEATURES better than most NEW CARS! it was $50,000 on showroom ten years ago! YIKES! Heated and CHILLED seats, too! SUPERB! DON'T think the ACIURA is an AWD driver, but it MIGHT BE! it is HARD to ekkp on ALL THE MODELS from ALL the years! At LEAST you are not COOING over a GM car!  LOL! >>ALSO look into a good used SUABRU OUTBACK or FORRESTER! Use CONSUMERS REOPRTS to figure out WHICH ONES as they RATE all cars frmo testing! SUBARU had ONE or TWO bad years but THEY are RESPOSIBLE with recalss and GOOD fixes! In REALITY the BENZ tranny is BULLET PROOF as is the ENGINE! i NEVER see LARGE issues with a BENZ and I have fixed ars for TWENTY PLUS years since I was 15 an ogt my FIRST BOSS 302 EURO cars are REALY THE BEST to buy as they were MADE to run on the AUTOBAHN all day long and NOT GET HOT at 150 MPH! TRUST MY I have DRIVEN THAT FAST! There are GREAT USED AUDI A8 cars out there an also great AUDI S6 cars as well if you like V8 cars! i prefer SMALL turbo charged engines and SUPERCHARGED AUDI 3.0 lighter cars the MOST! HAPPY HUNTING! Taker a BRAND NEW AUDI A3 for a TEST DRIVE someday soon! They are like SILENT BULLETS! Made the way ALL cars should be made and GREAT for THIRTY YEARS +!  

2008 TL, if it has been taken care of, will still be reliable. That is one of the best years for the TL.The same can't be said for the C300. They aren't very reliable and the repair costs will suck the life out of you. Other than that, the MB will have more tech and safety features being that it's that much newer. 

"Better" in what context?

As they're both used vehicles, and considering the Acura is a 12-13 year old vehicle, this vehicle's history will be a very important factor if you're looking at reliability/cost of ownership.

I would not have either one. One is too old and the other is too expensive to fix.

Have not seen or heard good things from older Acura cars. The cheaper Mercedes cars have a lot more problems than the more expensive models and the prices for parts is very high in comparison to an American car.

A 12 year old Acura vs a 4 year old Mercedes? You really have to ask this?

Although Acura are nice, the Mercedes has the longest standing rating for excellence.