I was a paint rep for several major manufacturer's...I've sprayed many different kinds of clear. SPI's line of products, not just there clears will rival the big boys...It is worth your time to try their clear...while your at it, try their Epoxy, it is the best hands down. Excellent build, great adhesion, fabulous rust protection, superior sanding qualities, a price that won't hurt the wallet and I need to tell you...before I recommend a product, I abuse it to test it's limits. SPI Epoxy stood proud, even with the amount of abuse I put it through. Another reason I like their Epoxy is that it comes in a dark gray, you, having been in the trade for many years will understand that it's easier to get a panel straight when you prime with a dark primer for the simple fact that any imperfections can be easily seen in the reflection. SPI Epoxy is the only primer I'm using now...no more etch or 2K Primer for build, SPI covers all those needs.
Give it a try...you will be impressed.