It seems the
Terramar does not like a car in its vision as you boot the accelerator, even if its quite far away, travelling at speed and be well gone by time I get there. Result is that as soon as push pedal the full on collision assist stops me before even crept a yard.
This behaviour is very similar to the "Rear Traffic Alert", which is supposed to
help the driver while backing out of a driveway, for example, by looking for any oncoming traffic from either side. But in reality, it overzealously intervenes and slams the brakes in any sight of a vehicle at the back while reversing. For instance, there's a parking lane along the roadside, you're on that lane and making small manoeuvres to achieve a perfect parking position without creating any danger for the traffic coming from the back, and that traffic is flowing without creating any danger to you. But our "assistance" system intervenes at any sight of a vehicle at the back and stops you from reversing. Long story short, it's just a big annoyance and I had to turn it off. (Both in my previous car, a
Leon Mk3, and current one, a Cupra
Ateca)
This system uses the rear radars mounted inside of the both sides of rear bumper. Another feature that uses those radars is the Side Assist (also called Blind Spot Monitoring) and it works well, I don't have a
problem with it.
While looking at the
Terramar's parts illustrations in the online parts catalog, I saw that some models have two front radars on the sides of the front bumper, just like the rear ones. I guess the one on the same side with the passing car on that roundabout is the culprit of your
problem. Its predefined sensing range is probably too wide and the car that has just passed falls in that range. Such a situation was/is never a
problem with centrally mounted single radars.
Now, I'm not sure whether your
Terramar has two front radars but I suggest you to check the driver assistance options list, by pushing the driver assist button and bringing up the list on the central display of your instrument cluster. (That button in my
Ateca is at the tip of the left column stalk, yours should have one too, somewhere around there if not the same place) When that scrollable list comes up on the display, check if there's any variant of the front collision, front assist, front traffic or something like that. I'm not suggesting to turn the front collision warning off completely, I'm just wondering if there are any switchable secondary option there, other than the main straight-on collision avoidance, as it is for the rear radar functions: You can turn off that annoying rear traffic alert, but keep the blind spot monitoring on. My thinking is that if your car has two radars on the front and this is also the case for front radars, that secondary function might be turned off.
Sorry for the long post, hope I have managed to explain it well enough. There may be a slight chance that I happen to be right, but no harm in checking, I guess.
Regards,
Serdar