You have to replace the rear axle with aluminum wheels as the factory ones are plastic.  Keep in mind that Ninco uses 2.48mm axles instead of 2.38mm axles like everyone else.  So it’s not just as simple as putting on a set of wheels and you’re off.  The chassis is generally good as it’s a solid flat piece of plastic.  IIRC the Merc DTM is an inline FK180 long can motor so you shouldn’t have the Ninco hop that is very common with the anglewinder cars.

Ninco just like everything else can be made to run smooth and fast, it just takes work.  Slot.it has really spoiled most people in being able to pull one out of the box and have it run nice.

Here’s a post I just came across for those looking for a Q1 car to tune.

https://www.slotcarillustrated.com/portal/forums/showthread.php?t=59975

I just realized those are Carrera DTM cars and not Ninco.  Sorry for the confusion.