Always wanted to ask... What's the purpose of those bent parts on the rear wheel opening moldings? The first time I saw one I thought it was a defect or something. Any ideas?

I believe that this flared part of the wheel arch, is there to pass homolongation rules for the USA market. More specifically, the distance of the wheel arch and the wheel must be at least X amount and when that is not the case then manufacturers raise the wheel arch just a tiny bit.

In some cases, the manufacturers don't make separate wheel arch parts for the USA market (like when the arch is not plastic), so they screw a set of extensions by hand.

I could be wrong, but at least that is what I remember. Please correct me if I'm wrong.

I think it's a styling/ aerodynamics aid. Always thought it looked a bit superfluous though.

Here is a video that shows the arch extension, on an Audi RS3 for the USA market (at 3:45 ...):

[ame]https://youtu.be/ZBiYn0l47XQ?t=225[/ame]

Good spot, it may well be that. For the widest 225 tyres they had to slightly increase the width of the tyrewell?

It's like mm's though on the fiat....i think.

Seriously, how does this small extension affect anything? I understand extending the whole arch, but only one short section? What's the practical point in it? Looks to me just like weaseling a way around the regulations.

Also, it doesn't seem to be exclusive to the US market. Here's a photo showing a UK version with the same arch extension.

Yes our UK car has them - I think they all do for the reasons Venezia has already stated. Nowt to do with aero - way to small - and slow(!) for that

Goodcoin said:

Also, it doesn't seem to be exclusive to the US market. Here's a photo showing a UK version with the same arch extension.

Click to expand...

That'll be for money's sake. Why have 2 different mouldings when it's required for one country but of no consequence in any other. One less thing to keep multiple stocks and production processes for.

Garree001 said:

That'll be for money's sake. Why have 2 different mouldings when it's required for one country but of no consequence in any other. One less thing to keep multiple stocks and production processes for.

Click to expand...

Yeah, that makes sense.

Can’t we come up with a better excuse when people ask.
Perhaps they serve a very minor role but let’s them more exclusive,
“ they create an anti spray vortex to reduce spray at high speeds

Parked next to a Range Rover Evoque the other day, and that had the same type of wheelarch "extensions" as the 500X, but slightly bigger. I suspect it's an airflow management tweak.

Possibly an airflow tweak but the 500X is a brick at the front, brick at the rear, high ground clearance (no sneaky airflow & ground effect tweaks) etc.

Can't really imagine that the little lip is a medium/large/critical airflow feature.

Also since when did road car manufacturers give a monkeys about airflow disruption/turbulence, spray, etc behind them?

Anyone from the FCA or JLR design departments care to enlighten us?

I was looking at them on car. The wheel arch mouldings without them don't extend the full width of the tyre. The bits that stick out however, do. I think they're there to stop spray and mud marks on the side of the car. Kind of a mini mud flap. Simple as that.

Pic to make my point.

Garree001 said:

I think they're there to stop spray and mud marks on the side of the car. Kind of a mini mud flap. Simple as that.

Click to expand...

But why only that short fragment then? Wouldn't it make more sense to make the extension as long as possible, to cover as much estate on the side of the car as possible?

Goodcoin said:

But why only that short fragment then? Wouldn't it make more sense to make the extension as long as possible, to cover as much estate on the side of the car as possible?

Click to expand...

Not really. They wouldn't be able to flog accessories like a set of full sized mud flaps then. Project the key area such as the boot lip, so that customers are satisfied, anything more you pay for.

VeneziaBlue500x said:

Here is a video that shows the arch extension, on an Audi RS3 for the USA market (at 3:45 ...):

https://youtu.be/ZBiYn0l47XQ?t=225

Click to expand...

I thought it was initially styling but when VeneziaBlue came up with this explanation I believe this is the reason. I looked at where my flares sit on the wheelarch and could envisage with 225 tyres they'd be just covered by it.

Would have been perhaps an idea to flare the wheelarches all around just a touch. Maybe not to the extent of an Audi A6 allroad, but a little. Maybe they didn't go that way to cost save and/or to maintain the "cute" look.

Looking at the photos it does look like they’re to stop spray hitting the paintwork from the back wheels