So, I have a couple issues to mention regarding this debate on the vehicle RAW, and maybe it will extinguish any embers of here. I'm sorry it's long, but maybe it will help when these rules get their turn in the Errata process.
Fact is, per the RAW, there's no right or wrong way to rule this. No one can "win" this discussion, and all interpretations are equally valid and invalid at the same time. Here's why:
Looking at the RAW, there is no guidance whatsoever on when or by how much to adjust the Handling Threshold to account for the maneuver the pilot declares. Nor is "something tricky" defined in any terms that would lead one to believe that "hairpin turn at high speed" is intended to use the baseline number for such a maneuver because the GM can arbitrarily and with no guidance provided in the RAW change this threshold at a whim "based on the difficulty". For example, if I as the GM think a hairpin turn is harder than vehicular stealth, then I am probably cranking that Threshold up, not down.
There's also no guidance on when or by how much to adjust Thresholds up or down. So, there's no written basis for arguing that the GM should adjust downward for anything less than a hairpin turn at high speeds, nor upwards either. That interpretation is a personal one not supported (nor denied) by the text. The text is simply not clear enough for those assumptions to be made in either direction. It’s a complete guess by the GM, but one with devastating consequences if their best guess results in the inability to avoid a crash.
There was also a notion posed here that there is no Threshold involved when using Opposed tests, which is not a complete statement. Per the RAW, the GM (again at their whim via the use of the word "can") is also free to call for a secondary test after the Opposed Test.
Side note: This second test is called a Simple test in the text, not a Handling test, even though it uses the same dice as a Handling test, so it's unclear to me if they should be considered as different in some way--ie, does failing it not result in a crash? The Crash rules state you crash when you fail a Handling test, which this is not labeled as. I assume this is a typo and should be a Handling test.
There are also no examples given of what circumstances would call for using two driver's skills against each other for the Opposed tests. For example, if I am weaving in and out of traffic to evade pursuit, is that a Handling test or an Opposed test? Technically, I'm just trying to avoid hitting other vehicles at high speed, like an obstacle course. So is my pursuer. What's the intent here? No way to know this either. It's just a different way to roll the dice if it makes more sense to the GM.
The sum total assessment here amounts to giving the GM the advice "do whatever you want, just use this one dice roll, and make sure to penalize the dice pool for the speed".
Was the intent to be this vague, and leave the table hanging in the GMs whims? As written, we can't even have a meaningful discussion about it, because no one can be right or wrong. There’s no guidance, and thus no real “system” to follow.
But maybe that's uncharitable of me. I get that way sometimes.
Let's assume I am. What other tools are there? Perhaps the Thresholds table on p.36 is supposed to be the guidance for the GM here, and I'm wrong that there's "no guidance".
Threshold Chart states:
(3) Normal starting point for Simple tests. Complicated enough to require skill. Shadowrunners are expected to be more competent than normal people, which is why game thresholds are based here. Shooting a window out of a nearby buiding.
(4) More dificult, impressive enough to accomplish. Shooting an enemy in the window of a nearby building.
So, even here, I am still left to interpret the wording. However, with this standard as the only guidepost, is any GM ever going to look at this chart and adjudicate "tricky" maneuvers downwards from the baseline Threshold in the Rigging section? Based on this chart, I would personally put "hairpin at high speeds" around a 5 from the chart guidance. It's certainly not a 3 on this scale. However, given that this is the case, it also follows that driving has a different scale in the RAW than does the rest of the game. A 3 is "normal" tasks in the table, and Ford Americar Handling is a 3 to do "tricky" things. Unless the Americar is really supposed to be a 3 because it makes “tricky” (4) into “normal” (3) instead, the scales don't seem align, even if we use these vague terms to guess around.
Just to clarify, again, I'm not saying that the downward adjustment theory is wrong/bad/incorrect. I'm still saying there is no "right", because the RAW doesn't establish what "right" is, except As Thine GM Dictateth (so long as the modifiers are used).
I’m also saying that the only possible guidance that exists is suggestive that upwards is the correct direction, but I can only hope to draw a GM like Michael when playing, as his take is much more player-friendly.
IMO, it would be clearer if Handling rating was expressed as a modifier to Threshold tests to control the vehicle. The Threshold table shows what the thresholds should be for different types of tasks. This would align the Rigging scale with the game scale.
The idea being aimed at is the traditional one that different vehicles should affect Handling tests. That’s a solid goal, always has been. Personally, the easy fix is to subtract 3 from the Handling listed and make this a modifier to the normal Threshold guidance. That hairpin maneuver may be a 5, but in a truck it's a 7. Then the system is unified to a core guideline, not making it's own separate one. Then make vehicle rig implants reduce the Threshold by their rating, and then I feel like a kick butt rigger in the 6E system, even driving a brick on wheels.
Regardless, as it stands, the debate is currently pointless, and we all should leave it behind until and unless it's addressed. Further questions should be answered as "that's up to your GM".
I can't expect the team to rewrite the Handling mechanic on my analysis though. There may be other factors I am unaware of too. So instead, to better approach this issue and enhance playability, if the Handling numbers/scale are to stand as written, then I would suggest that a maneuver threshold modifier chart would be in order for the Errata. There are also no other dice pool modifiers suggested for things driving on gravel, slick surfaces etc, which presumably would be their own adjustments to dice pools? A table for that would be helpful, unless the RAI are not to fuss with those things, and simply let Speed be the only factor the game cares about measuring. If that's the case, it would be good to have stated explicitly as well, so GMs don't start stacking on the penalties past the system tolerance limits.
Thanks for reading. I hope it helps somehow.