[MENTION=60930]4gin007[/MENTION]
Unfortunately [MENTION=49]Sungod[/MENTION] is right, most dealership and even 3rd party technicians tend to be more parts replacers than anything else. It doesn't help that Toyota's FSMs and Troubleshooting charts read as basically "Check Powers, Grounds, Continuity, then replace these things." Not to mention most of the information that you could use for diagnostics are either not available to even the dealer technicians or so buried in TIS it's not worth it for a flat rate mechanic to even attempt to find. These days technology is so far ahead of most technicians compared to what it used to be that they have no idea what they're working on half the time. Most guys look at you like you have two heads when you talk about using a DSO to diagnose a CANBus system or current ramping to test coils and injectors. What's even worse is that most shops, dealers, and technicians can't afford that equipment and training and/or don't want to bother learning that stuff.
Not to say that the older guys aren't good mechanics, but a large majority fall under the "can't teach an old dog new tricks" category, while most of the newer guys are not being taught right and/or given the opportunity to learn more than "replace this if the FSM Troubleshooting chart says so." We don't rebuild alternators, starters, ect. anymore; we replace them, hell engine rebuilding is rarely done at the dealership aside from the current slew of 2.4L campaign motors (even then all we're doing is pistons and rings and nothing else.) The system is set-up to sell parts and assemblies, not diagnosis or repair; warranty time is so bad these days that you're lucky if you break even on some of these campaigns and recalls.
Which brings me to the question you asked earlier [MENTION=60930]4gin007[/MENTION]. It doesn't really matter if the technician knows what he's doing or doesn't know; it's all about "can I make my hours." In the case of the 4Runner Dash it's 2.2hrs to replace the entire dash pad, I believe it's something like 3hrs+ on AllData (I'll check tomorrow if I can.) That means the technician is basically already being cheated out of about .8hrs on the job before he even gets it; the mentality with most warranty jobs is "how fast can I get it down to." Most technicians are paid flat rate, so the faster we get that warranty job done, the better chance we actually get paid properly at the end of the pay period. Due to how little "meat on the bone" there is with warranty (in some cases where they even come up with the numbers is beyond most of us since it often takes longer than what they pay, so the techs lose money on the job) most guys either aren't enthusiastic to do the work or just try to rush it; which can lead to mistakes (i.e "why bother disconnecting the battery? That's extra time under the hood! Just don't turn the key on and try not to short anything out!" or "Just bend that bracket a little and you can slide that thing right out!") You could inform the service writer about any mods you've done and/or to be aware of things once they start getting back there; but depending on the kind of technician you get (and let's be honest, it can be anywhere from "who let this Lube Tech work on this car!?" to "Damn dude, you sure you don't run your own ShowCar shop!?") they might not even bother to read anything beyond "Replace Dashboard under Warranty... 2.2.hrs." In the end it's up to you, the best you can do is to hold the dealership accountable for their quality of work; even if you have aftermarket components, they shouldn't be blaming YOU for shorting out something because they were rushing the job and not paying attention.
To give you a frame of reference, we had a CSP on 2nd Gen Prius combination meter replacement which requires the entire dash to come off; it pays only 1hr to take the dash off, disassemble the instrument cluster portion on the dash, replace the combination meter assembly, and put it all back together again. I've got it down to about 45~60min (pulling the car in, getting parts, ect.) if I'm doing good, most guys don't want to deal with it because they'll never break even on the job. I had to replace one on a 3rd gen Prius under warranty (I forget what it paid, but it was ridiculously light,) I found that while the FSM said to remove the entire dash like the 2nd gens; if I popped the center portion of the dash pad up, then tilted the cluster I can get it in & out in 1/3 of time time it would take if you removed the dash as per FSM (but you have to be careful and know how to twist it. I could easily see someone rushing breaking a clip or two on the dash or scratching the cluster if they were trying to rush it with my method.) Another example is the "just replace the actuator without cracking the transfercase open" method that gets mentioned every now and then on the forum; almost every time it's ever been mentioned there's a slew of "the o-ring leaked shortly after" or "the actuator stopped working after I did this" or "I couldn't get the timing right ever since I opened it up."
opcorn: This is gonna get interesting! 
