I have three TS rally cars. Two are resin: a MKII Escort which is excellent on the eye and runs very nicely - not a performance winner but easy to drive and powerslides happily. Needed a bit of work to trim some resin off the inside to make the guide sit properly, but otherwise just the normal gluing and truing; a Audi Quottro - took a bit more work having the body lowered, pinion needed pushing on its shaft a bit more, motor needed additional support to stop it rocking and front axle needed some movement restricted - then normal gluing and truing of hubs and tyres.
Then I have one plastic TS rally car - an Alpina that runs very happily and only needed the front axle sorting out and then ran fine.
Note the later models quality is much improved (see front page pics of the stratos) and use tampo printing for the logos whereas earlier models (don;t know the cut off model) use stickers and quality was not quite so consistent.
I really like them and a Stratos will be added to the line-up once the Pirelli livery is out.