The Shop Checklist for Gtechniq Coatings, OBD GPS Trackers, and a Nissan Audio Upgrade

This checklist is for shop owners and installers who handle ceramic coating appointments alongside electronics work. I have been handling coating and electronics orders for six years, and I have personally made seven significant mistakes that added up to roughly $4,800 in wasted product, labor, and customer goodwill. This is the list I wish I had in my first year.

There are seven checkpoints. Work through them in order, and you will avoid the issues I hit with coatings, installed electronics, and shop air equipment.

1. Build the job map before you quote

When I put a B2B order together, I try to think like a customer: what is actually included? For a coating appointment, is prep included? Trim masking? For an OBD GPS tracker plugged in car port, does the customer expect the unit to work with a mobile app? For a Nissan car audio player, does the quote include the wiring interface that makes the steering wheel controls work? You can quote a low number and add fees later, but that creates the exact kind of trust problem I don't want.

I have learned to ask 'what is NOT included' before 'what is the price.' The vendor who lists all fees upfront, even if the total looks higher, usually costs less in the end. I list prep, supplies, labor, and any interface modules as separate line items. It makes the proposal look less sleek for a moment, but it makes the invoice defensible later. And if a customer asks for a 'green' option, I don't throw around words like 'eco-friendly' without documentation. Per the FTC Green Guides (16 CFR Part 260, ftc.gov, accessed April 2026), environmental claims need substantiation. That keeps the quote honest.

2. Lay out the coating system and the brushes

For Gtechniq jobs, I lay out the actual product bottles before the vehicle is pulled in. If the job is a boat, Gtechniq Marine Ceramic Top goes on the list. It was still an active SKU as of our Q1 2026 orders, but product lines change, so I verify the current Technical Data Sheet before promising anything.

I also keep a Gtechniq detailing brush set in the prep tub. Different brushes—actually, three sizes. I used to rely on microfiber towels for emblems and grilles because I thought brushes would leave marks. Then I found the dirt left behind around a badge on a white SUV. A proper brush set reaches panel gaps and trim edges without dragging contamination across the paint.

3. Prep the surface and read the conditions

This is where coating jobs die. A top coat cannot fix contamination that is already on the surface. If you apply Gtechniq Marine Ceramic Top over a surface with old wax, tar, or polishing oils, you are locking that layer in. In September 2022, I did exactly that on a customer's boat. It looked fine for two weeks, then the water behavior went patchy. The redo cost $890 and a one-week delay. Lesson: prep and cure are separate jobs, not optional upcharges.

Check the ambient conditions too. If it is too hot, too cold, or too humid, the coating may flash unevenly. I don't have hard data on the current application ranges for every Gtechniq product, so I read the Technical Data Sheet for the batch I am using. I used to think one temperature range covered all coatings. It does not.

4. The OBD GPS tracker: trust it, then test it

An OBD GPS tracker plugged in car port is easy to install. Honestly, the wiring part is simple. The dangerous part is the sleep behavior. Why does sleep matter? Because if the tracker doesn't go to sleep with the vehicle, it can drain the battery while the car sits.

Before I close up the install, I measure the current draw on the tracker with a clamp meter. One customer-supplied unit drew 0.3 amps. That does not sound like much, but left for a week, it pulls more than 50 amp-hours from the battery. The tracker had no accelerometer sleep mode. If I had trusted the claim on the box, the customer would have come back to a dead car.

Also, confirm the OBD port is still reachable. On some Nissan models, the port is tucked behind a panel. If the customer needs to unplug the tracker for an inspection, they should not need a trim tool to get to it.

5. Nissan audio player: check compatibility before the dash comes apart

For a Nissan car audio player swap, the number one mistake is ordering the head unit before checking the rest of the system. Steering wheel controls, parking brake signal, factory amp, and backup camera can all require an interface module. If the quote does not include that module, the customer finds out at 4:45 PM.

The counterintuitive step is to measure behind the dash before you buy. We once installed a shallow-depth unit in a Nissan and found the rear of the cage hit the HVAC housing. We had a unit in hand and an unhappy customer. Looking back, I should have taken the dash measurement seriously before approving the order. At the time, I thought the manufacturer's depth chart was enough.

If the same vehicle needs a new OBD GPS tracker, run that cable before the radio goes in. It takes ten minutes with the dash open and two hours if you try to fish it behind the console later.

6. Portable tire inflators: duty cycle beats peak PSI

A lot of customers search for 'best portable tire inflator 2025 Wirecutter' before they ask what we stock. I cannot speak to Wirecutter's current ranking—it changes faster than my inventory list. What I can tell you from using four different units in our shop is the buying checklist: duty cycle, pressure accuracy, cable reach, and replacement part availability. In that order.

Peak PSI is a marketing number. A 150 PSI inflator that shuts off after 90 seconds is less useful for a pickup tire than a 100 PSI unit that runs for 15 minutes without melting. If you are buying for the shop, pick the unit you can open when the hose cracks. Our least expensive inflator lasted the longest because the parts were easy to get.

7. Test, label, and hand off with a note

Before the customer arrives, I run the same test loop: coating is applied and curing; tracker is reporting; head unit keeps its memory after the ignition goes off; backup camera switches cleanly. For the inflator, I compare the built-in gauge to a known-good digital gauge. That is how I caught a 7 PSI error. The unit said 35 PSI, but the tire was at 28. That kind of error ruins a road trip, and I would not have found it without checking.

I have caught 47 potential errors with this checklist in the past 18 months. Most were small. One was a coated vehicle with the wrong prep product. Another was a tracker that would have drained a battery during a two-week airport parking session. The checklist catches them before the customer does.

A few notes I add to every order

Don't apply a top coat in direct sunlight unless the Technical Data Sheet says it's okay. I don't have hard data on every Gtechniq formula, but fast solvent flash has caused me headaches on hot shop days.

Don't hide fees in a big total. Transparent pricing builds more long-term trust than a low quote followed by an unexpected prep charge.

And don't assume the 'best' product someone saw in a review is right for their use case. Send them to the current review and explain why duty cycle matters more than the number on the box.