Most modern cars have a limp mode when the
detects a fault but the downside to Renaults is that they use a different protocol in their
's and very few garages apart form the dealers have the compatible kit to read the fault codes - thus making repairs that much more expensive. Plus Renault guard there technical manuals like gold dust and guard their copyright jealously.
Thankfully both cars I drive and service don't suffer such problems. I have never really concerned myself regarding how a car looks or how fancy the wheels may be simply because I can see neither when I'm inside. I take the simplistic view - any car is better than walking.
One thing to ask your self is this. Why are Renault second hand cars so plentiful and cheap. I think you'll find the anwer is that they just become uneconomic to repair. For example my neighbour offered me his 2007 Lag II a few weeks ago. It was going reasonably well, had 82K on the clock. He simply said if you can beat £400 it's all yours not because I was a neighbour but that was the best price anyone else had offered. To make it fully reliable he need to spend £2000 on it which was more than it was worth.
I ain't setting out to knock Renaults (there are worse makes out there) but when buying a second hand Renault you need to keep a level head and not be swayed by looks or the bells and whistles. Either that or have deep pockets.
Good luck with your search and I hope you enjoy whatever you decide to buy.