Is volkswagen Tiguan reliable car for Texas, California environment for 10 years

Only for the first 80K then things start happening, maintenance costs are very high and you must do the extreme maintenance due to the areas driving conditions or problems will start showing much earlier.

Believe it or not, VW is now a high-end car, and high-end cars from places like Germany and England were designed to be bought new and sold before they hit sixty-thousand miles. If that defines you, then VW might be OK for you. After that, those cars become a maintenance nightmare, really expensive. If you want better reliability, I'd suggest you look at Lexus, Mazda, or Toyota. I'd recommend the Mazda CX-5, or what I'm waiting for, the CX-70 phev.