Re: Wife is behaving weird. Need some input
Here's what i'd do. I'd find out if she really is at the restaurant, and if she stays for the entire time. Does she leave with someone else and then come back for her car?
Put a VAR in her car. Get a good SONY brand unit, they run about $65 at WalMart. Put top quality batteries in it. Use strong wide velcro to attach it securely in her car. Under her seat is fine, or under the dash. Play with the unit for a bit before you install it so that you know absolutely positively how to operate it. Make sure it is set to silent mode so it doesn't somehow make noises. You can snip the plug off of old cheap earbuds and plug it into the earphone jack. This should ensure the speaker is bypassed.
Place the VAR so that she can't see it easily, and make sure it is secure so it won't fall out. The VAR will capture phone conversations she has. People think it is totally private in their car, and will talk unguardedly. Many cheaters have been caught this way. We had one member here who used a VAR to discover his wife was not cheating but had some serious issues in the marriage. The guy used the info to change some things he was doing and he rescued his marriage. Whatever data you get will be good to have. Nothing from the VAR is ever revealed to anyone, not even your wife. The VAR is for your info only.
I would also place a GPS unit in her car. This is a more expensive route to go, and could wait until you've gathered the VAR information for a few weeks. Alternative options are to hide your cell phone in the car (set to silent mode plus earbuds plugged in) and turn on "find my phone" or whatever similar function your phone and carrier offer. Be sure to activate GPS on your phone. Your phone battery should be good for the few hours she is at lunch. Stash it where she won't find it. Watch where the car is in real time from your computer at home.
Another alternative is to follow her a few minutes behind to the restaurant. Park where you're not obvious. This won't work if you have a unique car. Be your own PI to see if she is at the restaurant, and when she leaves. When she does leave, drive home a different way than her so she doesn't see you.
Review all the phone and credit card statements. You're looking for anything odd. Massive numbers of texts, calls at odd hours, all to the same number. Look at the credit card statements to see if she's really buying lunch on those days (the date the charge goes through could be 1 to 3 days later). Are there any odd things which could be gifts, or hotels?
Her changing in the bathroom seems quite odd to me, given that she didn't ever do that before. Do you still have sex with her? Has her personal grooming changed? If so does it coincide with her changing in the bathroom and this new friend?