Gtechniq is a British coatings company with an unusually research-led posture — the founder’s background is materials science, and the product naming reflects a lab rather than a marketing department. Crystal Serum Ultra is installer-only; Crystal Serum Light is the consumer-accessible version of the same chemistry; C2, C4 and I1 cover the sealant, trim and fabric cases.
What you are buying is hardness and longevity claims that are actually stated in measurable terms, and a company that publishes what a coating will and will not do. Gtechniq is also one of the few brands in this category with open wholesale registration rather than a closed dealer network, which is why it reaches Canada without an exclusive importer in the middle.
Where it disappoints is the everyday chemistry. The wash and decontamination products are competent rather than exceptional, and if you are buying Gtechniq for shampoo you have probably bought the wrong brand. Buy it for the coatings and the trim work.