18 zf800trail.  Just trying to decide which route to go?  Do the springs make that much difference?

2018zf800trail.
The previous weekend I did a 100+ mile trip and the machine ran great.   I went to load it on the trailer this past Saturday and it was really loud.  Like it had straight pipes.  I did see a lot of dust blowing over the rear driver side tire. After about a minute or so it was quiet again.  So I loaded and went riding.  Same thing happened and while it was loud I did get one backfire upon acceleration.   After a minute or so it was quiet and ran great for the day.  Got home and same thing.  I took off one heat shield and all my springs are there.  No visible exhaust leak.  Couldn't tell if the valves were noisy or not. 
Any ideas?

What would be better?  1.5 " lift or going up two sizes on the tires.   Currently have the lift installed and tires on the way.  Thinking about removing the lift and just using bigger tires.  I know I could run both but it is not what I am asking. 
Thoughts?

I remember reading that I need to install wheel spacers with a 2" lift.  I can't find what size?  Does anybody know?

Looking at two types of trailers, 6/7x14 open aluminum and 6x10 steel frame enclosed.  The enclosed is $500 to $1000 more.  Having a tough time deciding between the two.  Obviously they each have benefits.   What would you choose and why?

https://youtu.be/z
dVtVrNZn4w

I understand trail 50" and ex is 60"  What is this 53" wide sxs?

I just bought a new 2018 left over zforce 800 trail.  It has 7 miles on it and while driving it out of my garage I noticed the oil light came on after it was running for a bit.  It came on for a brief second then went out.  It happened 3/4 times while it was running.  It happened at idle and the light would not stay on.  If it was a oil issue wouldn't it stay on?  Looking for ideas before I bring it in.  Where are the wire connections for the oil psi sensor?

i see a lot of problems where the stock filter is poorly made and the intake is in a bad location.  has anyone tried the mesh screen arctic cat uses on the snowmobiles at the intake?  i have ordered the uni filter and pre-filter but these pre-filters are the same or similar to the screen cat uses.

Looking at these two model years, both are brand new.  The 2018 is 2k cheaper.  Is it worth it?  Any changes or updates from 18 to 20?  Any issues with either model?  They seem like a great machine except for the airbox design.  Is there an update or better system out there for this?